Iran and North Korea have long cooperated in some aspects of their missile development and probably in some aspects of their nuclear programs as well. Some of the details of this cooperation are clear, but many are not—at least at the open-source level of data available outside the intelligence community. This raises critical issues in evaluating the progress each country is making in the development of its nuclear forces, and how much cooperation they still have in shaping their missile forces.It also raises the issue of how possible it is to establish effective arms-control efforts and stable structures of deterrence when key aspects of each country’s military development can be affected by the actions of a distant and very different power. Containing, deterring, and defeating either Iran or North Korea is difficult enough when each nation is treated separately. It becomes far more difficult to the extent they are cooperating to develop missile and nuclear forces.A Strategic Alliance Between Seeming OppositesAny such alliance is scarcely based on common sets of values. Iran and North Korea are very different powers. Iran still has important democratic and secular elements, but it technically is an Islamic theocracy center around Persian culture and the goal of revolutionizing Islam. North Korea, or the Democratic People’s Republic of Korea (DPRK), has become a hereditary autocracy or dictatorship, although it technically is a secular, anti-religious, Marxist authoritarian one-party state.Two problems Iran and North Korea share, however, are similar and critical security problems and challenges in modernizing and strengthening their military forces. Since the fall of the shah and Khomeini’s religious revolution in 1979-1980, Iran has provoked a hostage crisis with the United States and then kept itself an enemy of the U.S., it has been a source of religious extremism in much of the world, sponsored terrorist attacks, and been hostile power to most of its Arab neighbors.With the exception of limited arms sales and transfers of military technology by Russia and China, Iran’s actions have alienated so many states that it has lacked support from a major outside power in developing its military forces. Iran has been forced to turn to the international black market in arms sales and military technology, and has faced critical problems in importing arms and modernizing its military forces. Furthermore, its economic policies, war, and sanctions have badly weakened its economy, and it has a limited industrial base. This has virtually forced Iran to turn to any ally outside the region that it can find.Recent OPEC reports also show that Iran has gotten only marginal benefits from the easing of sanctions resulting from its nuclear-arms agreement. Its petroleum-export income peaked at $99 billion in 2011, in constant 2016 dollars. It then dropped steadily as a result of sanctions and the “crash” in oil prices in 2012-2014. It only rose from a low of $29.4 billion in 2015 to $36.2 billion in 2016. These revenues still leave Iran in a position to buy from North Korea, but they also force it to seek any savings it can find in buying arms and technology.North Korea, in turn, has been under a de facto dictatorship that has used the specter of foreign enemies to justify itself since the cease-fire in the Korean War. It initially had the support of the Soviet Union in creating what remains the most militarized state in the world, but it lost much of its Soviet aid in arms transfers following the death of Stalin, became caught up in the split between the Soviet Union and China, and then lost even more aid and support as the Soviet Union broke up in the early 1990s and China focused more on regional stability and trade. China has remained an ally, but has not given North Korea substantial military aid in the face of its violent provocations of its neighbors and confrontation with the United States. Like Iran, North Korea lacks major allies and is seen as a threat by many of its neighbors.North Korea also has to support one of the most militarized nations in the world with one of the weakest economies. Iran has oil wealth and large dollar earnings that it can use to buy arms, missiles, and nuclear technology. Despite sanctions and a crash in world oil prices since 2014, the CIA Factbook reports that Iran still had a GDP of over $1.4 trillion in 2016, a per capita income of $18,100, and exports of over $87 billion. The CIA puts North Korea’s GDP at an extraordinarily low $40 billion, its per capita income at $1,800, and its exports at $4.1 billion.There are no reliable estimates of either Iranian or North Korean military expenditures, but it seems doubtful that North Korea can afford more than 20 percent of Iran’s spending in dollar terms. If Iran has sometimes been desperate to buy arms and military technology, North Korea has always been desperate to sell arms and military technology, and it too is under intense pressure to find any ally it can outside the region. It is in the awkward position of being one of the most militarized countries in the world, and one of the least able to afford its militarism.Both countries also share a common strategic interest in creating strong missile and nuclear forces. Iran and North Korea do have large conventional military forces by regional standards, but all of the public reporting on their military forces shows that their internal economic problems and lack of outside support in arms transfers and sales of military and dual-use technology has led to a sharp deterioration in their level of military modernization. Many key elements of their conventional military forces—particularly their air forces—are aging and are of mediocre quality, with some elements bordering on obsolescence. The result is that both powers have been forced to look for some way to compensate for their military weakness in the face of hostile regional military power and U.S. power-projection capabilities.One way both countries have chosen to compensate for these problems is creating asymmetric forces that can fight in unconventional ways. Another has been to develop missile forces and seek nuclear weapons. Each has sought to use missiles and weapons of mass destruction to deter regional powers and the U.S. from using advanced conventional weapons against them, and to develop more effective ways of threatening their neighbors and the U.S. This may well have led both nations to cooperate in developing some aspects of their nuclear forces—although there is no hard public evidence of such cooperation in nuclear-weapons development—and has definitely led them to cooperate in developing their missile forces.The Uncertain Nature of Nuclear CooperationIt is important to stress the fact that much of the open-source reporting on their possible cooperation in nuclear-weapons development is contradictory and uncertain. There have been many reports of such cooperation from the 1990s onward, and many more surfaced as a result of the debates over the Iran Nuclear Agreement (the Joint Comprehensive Plan of Action (JCPOA) that was formally adopted Oct. 18, 2015, and Iran was formally stated to have implemented Jan. 16, 2016.There have also been reports that Iran has sent delegations and deployed scientists and technical experts to North Korea and that North Korea has sent its experts to Iran. In a number of cases, there have been claims that North Korea sent at least three delegations to aid Iran in its nuclear-weapons efforts, and that Iran sent observers to North Korean nuclear weapons tests—although exactly what a delegation could gain from observing an underground test is unclear.North Korea and Iran have openly signed agreements like their Scientific Cooperation Agreement at meetings like a summit of the 120-member Non-Aligned Movement (NAM) in September 2012. North Korea’s state-run Korean Central News Agency (KCNA) described this agreement as one for covering “cooperation in science, technology and education,” and some observers have noted that it was similar an agreement North Korea and Syria signed in 2002 that may have led to North Korea covertly giving Syria nuclear-reactor technology it could use for its nuclear program.A Congressional Research Service study published in February 2016—Iran-North Korea-Syria Ballistic Missile and Nuclear Cooperation—also states that, “Some press reports have pointed to alleged instances of nuclear-related cooperation, such as the possibility of Iranian officials witnessing North Korean nuclear tests.” There are questions about the accuracy of each of the sources the CRS study cites—although there have been other reports such a visit took place. However, other sources do indicate that a list of the Iranian scientists at the 2013 test was published in the Iranian official press and was later deleted.Most statements about actual nuclear cooperation have been vague, contradictory, or politically motivated. There have, however, been notable exceptions. One extraordinarily detailed article was published in February by two retired Israeli officers—Lt. Col. Dr. Refael Ofek and Lt. Col. Dr. Dany Shoham. The article was published by the BESA Center, a conservative Israeli think tank that has generally opposed the Iran nuclear agreement. It described Ofek as “an expert in the field of nuclear physics and technology, who served as a senior analyst in the Israeli intelligence community,” and Shoham as “an expert in the field of weapons of mass destruction who served as a senior intelligence analyst in the Israel Defense Forces.”The article noted the importance of the September 2012 agreement between Iran and North Korea and stated that:From the 1990s onward, dozens—perhaps hundreds—of NK scientists and technicians apparently worked in Iran in nuclear and ballistic facilities. Ballistic missile field tests were held in Iran, for instance near Qom, where the NK missiles Hwasong-6 (originally the Soviet Scud-C, which is designated in Iran as Shehab-2) and Nodong-1 (designated in Iran as Shehab-3) were tested. Moreover, in the mid-2000s, the Shehab-3 was tentatively adjusted by Kamran Daneshjoo, a top Iranian scientist, to carry a nuclear warhead. … Furthermore, calculations were made that were aimed at miniaturizing a nuclear implosion device in order to fit its dimensions and weight to the specifications of the Shehab-3 re-entry vehicle. These, together with benchmark tests, were conducted in the highly classified facility of Parchin. Even more significantly, Iranian experts were present at Punggye-ri, the NK nuclear test site, when such tests were carried out in the 2000s.\n\n\n\n… A meaningful event took place in September 2012, when Daneshjoo, then the Iranian Minister of Science and Technology, signed an agreement with NK establishing formal cooperation. The agreement formally addressed such civil applications as “information technology, energy, environment, agriculture and food.” However, the memorandum of the agreement was ratified by Ali Akbar Salehi, head of the Atomic Energy Organization of Iran. Iranian Supreme Leader Khamenei has since clarified that the agreement is an “outcome of the fact that Iran and NK have common enemies, because the arrogant powers do not accept independent states.” It is reasonable to infer that the agreement went far beyond its alleged civilian sphere.\n\n\n\n…The September 2012 agreement was probably intended to mask an evolving Iranian-NK cryptic interface, intended by Iran to compensate technologically for the following development…. A delegation of Iranian nuclear experts headed by Mohsen Fakhrizadeh-Mahabadi, director of the Iranian NW project, was covertly present at the third NK nuclear test in February 2013. This test was apparently based—unlike the previous plutonium-core-based field tests—on an HEU (highly enriched uranium) core nuclear device (as, presumably, were the fourth and fifth nuclear tests, which took place in 2016). In 2015, information exchanges and reciprocal delegation visits reportedly took place that were aimed at the planning of nuclear warheads. These include four NK delegations that visited Iran up until June 2015, one month before the VND was completed. It may be noted that in August 2015, a new gas centrifuge hall apparently became operational in the NK main uranium enrichment facility.\n\n\n\nThe current Iranian-NK interface, which appears to be fully active, presumably serves as a productive substitute for the Iranian activities prohibited by the VND. It enables Iran, in other words, to continue its pursuit of NW.A Lack of Official U.S. Confirmation That Such Cooperation ExistsThe problem with this article and other detailed reports is that it does not provide hard evidence or clearly reliable sources for the statements that confirm Iranian and North Korean cooperation in developing and producing nuclear weapons. This is particularly important because the U.S intelligence community has been asked for nearly two decades whether it has such proof. It has never confirmed such cooperation, although it has repeatedly described their cooperation in developing missiles. The issue of official U.S. confirmation became particularly serious during the congressional debate over the Iran Nuclear Agreement in 2016, when Sen. Ted Cruz, R.-Texas, asked James Clapper, then director of national intelligence, “Has the U.S. intelligence community observed any possible nuclear collaboration between Iran and North Korea?”Clapper never publicly replied in any detail, although some retired U.S. intelligence experts, U.S. officials, and military officers have implied such cooperation has existed in the past. For example, Maj. Gen. Robert Scales, a former commandant of the U.S. Army War College, stated in an interview with Fox News in January 2016 that, “We know that the Iranians were at the last nuclear test a couple of year ago, [and] we know that the Iranians are helping the North Koreans miniaturize their nuclear weapons.” He indicated that the North Korean nuclear program experienced several failures until it received assistance from Iran. “What does this say about our nuclear deal with Iran?” Scales asked. “It says Iran is able to circumvent it by using their technological colleagues in Pakistan and their test-site facility in North Korea to push their own nuclear ambitions.” He added that “the Iranians and North Koreans are both developing long-range ballistic missiles by collaborating together.”It is also interesting that the Congressional Research Service study cited earlier reported that officials in the executive branch had stated that there is “no evidence that Iran and North Korea have engaged in nuclear-related trade or cooperation.” This wording does not seem ambiguous, but one former CRS expert on the subject, Larry Niksch, noted such statements might not be fully accurate in testimony he gave after he had left the CRS, and cited a wide range of indicators that nuclear cooperation might be taking place:…The unwillingness—of the executive branch of the U.S. government to disclose information about the Iran-North Korea relationship. There have been some public disclosures about Iranian-North Korean collaboration in the development of missiles. On nuclear collaboration, there has been a virtual blackout of public information. …This blackout includes this denial, avoiding specific answers when asked about this, and denial statements in unclassified and declassified U.S. intelligence assessments. …Thus, little has appeared in the American news media about this. There are, however, a couple of notable exceptions.\n\n\n\n…In September 2012, Iran and North Korea signed an agreement for wide-ranging technology and scientific cooperation. This did draw a reaction from Obama administration officials, which The Wall Street Journal reported on March 8, 2013. The report asserted that Obama administration officials were concerned that the head of Iran’s atomic energy agency was present at the signing ceremony. It described U.S. officials as concerned that Iran and North Korea share nuclear technology.\n\n\n\nThe Washington Post reported on November 7, 2011, that “secret intelligence” provided to the International Atomic Energy Agency showed that Iran had received “crucial technology” from North Korea for the development of nuclear warheads. This included mathematical formulas and codes for warhead designs, “some of which appear to have originated in North Korea.”Daniel R. Coats, the director of national intelligence appointed by the Trump administration, did not make any new declarations about Iranian and North Korean cooperation in his annual Worldwide Threat Testimony to Congress on May 11. He made it quite clear that the U.S. intelligence community recognized a nuclear and missile threat from both Iran and North Korea, but he dealt with each country separately and in notably different ways.Coats described the nuclear and missile threat from Iran as follows:Iran’s implementation of the JCPOA has extended the amount of time Iran would need to produce enough fissile material for a nuclear weapon from a few months to about a year. The JCPOA has also enhanced the transparency of Iran’s nuclear activities, mainly through improved access by the International Atomic Energy Agency (IAEA) and its investigative authorities under the Additional Protocol to its Comprehensive Safeguards Agreement. … Iran is pursuing capabilities to meet its nuclear energy and technology goals and to give it the capability to build missile-deliverable nuclear weapons, if it chooses to do so. Its pursuit of these goals will influence its level of adherence to the JCPOA. We do not know whether Iran will eventually decide to build nuclear weapons.\n\n\n\nWe judge that Tehran would choose ballistic missiles as its preferred method of delivering nuclear weapons, if it builds them. Iran’s ballistic missiles are inherently capable of delivering WMD, and Tehran already has the largest inventory of ballistic missiles in the Middle East. Tehran’s desire to deter the United States might drive it to field an intercontinental ballistic missile (ICBM). Progress on Iran’s space program could shorten a pathway to an ICBM because space launch vehicles use similar technologies.\n\n\n\n…Iran continues to develop a range of new military capabilities to monitor and target US and allied military assets in the region, including armed UAVs, ballistic missiles, advanced naval mines, unmanned explosive boats, submarines and advanced torpedoes, and anti-ship and land-attack cruise missiles. Iran has the largest ballistic missile force in the Middle East and can strike targets up to 1,242 miles from Iran’s borders. Russia’s delivery of the SA-20c surface-to-air missile system in 2016 provides Iran with its most advanced long-range air defense system.Coats gave the following description of such threats from North Korea:North Korea’s nuclear weapons and missile programs will continue to pose a serious threat to U.S. interests and to the security environment in East Asia in 2017. North Korea’s export of ballistic missiles and associated materials to several countries, including Iran and Syria, and its assistance to Syria’s construction of a nuclear reactor, destroyed in 2007, illustrate its willingness to proliferate dangerous technologies.\n\n\n\nNorth Korea has also expanded the size and sophistication of its ballistic missile forces—from close-range ballistic missiles (CRBMs) to ICBMs—and continues to conduct test launches. In 2016, North Korea conducted an unprecedented number of ballistic missile tests. Pyongyang is committed to developing a long-range, nuclear-armed missile that is capable of posing a direct threat to the United States; it has publicly displayed its road-mobile ICBMs on multiple occasions. We assess that North Korea has taken steps toward fielding an ICBM but has not flight-tested it…We have long assessed that Pyongyang’s nuclear capabilities are intended for deterrence, international prestige, and coercive diplomacy.\n\n\n\n…North Korea’s weapons of mass destruction program, public threats, defiance of the international community, confrontational military posturing, cyber activities, and potential for internal instability pose a complex and increasingly grave national security threat to the United States and its interests.\n\n\n\nNorth Korea’s unprecedented level of testing and displays of strategic weapons in 2016 indicate that Kim is intent on proving he has the capability to strike the U.S. mainland with nuclear weapons. In 2016, the regime conducted two nuclear tests—including one that was claimed to be of a standardized warhead design—and an unprecedented number of missile launches, including a space launch that put a satellite into orbit. These ballistic missile tests probably shortened North Korea’s pathway toward a reliable ICBM, which largely uses the same technology. Kim was also photographed beside a nuclear warhead design and missile airframes to show that North Korea has warheads small enough to fit on a missile, examining a reentry-vehicle nose cone after a simulated reentry, and overseeing launches from a submarine and from mobile launchers in the field, purportedly simulating nuclear use in warfighting scenarios. North Korea is poised to conduct its first ICBM flight test in 2017 based on public comments that preparations to do so are almost complete and would serve as a milestone toward a more reliable threat to the U.S. mainland. Pyongyang’s enshrinement of the possession of nuclear weapons in its constitution, while repeatedly stating that nuclear weapons are the basis for its survival, suggests that Kim does not intend to negotiate them away at any price.Lt. Gen. Vincent R. Stewart provided a very similar set of views in his first Worldwide Threat Assessment under the Trump administration on May 23. He provided more detail on Iranian and North Korean nuclear and missile activities, and expressed his concern about “North Korea’s proliferation activities,” but again dealt with Iran and North Korea totally separately. He summarized Iranian nuclear and missile threats as follows:The JCPOA has curtailed Iran’s nuclear program and has established benchmarks for the lifting of UN restrictions on the import and export of certain advanced conventional weapons and ballistic missiles through 2020 and 2023, respectively—pending Iran’s continued compliance. If the International Atomic Energy Agency (IAEA) reaches the “broader conclusion” that Iran’s nuclear program is peaceful before those dates, these restrictions will end. Since implementation of the JCPOA, the IAEA has been monitoring Iran’s nuclear-related obligations under the agreement. The agency continues to verify and report that Iran has not enriched uranium above allowable levels, maintains limits on centrifuge numbers, allows the IAEA to monitor nuclear fuel and heavy water stocks, and has been conducting enrichment R&D within JCPOA-prescribed limits.\n\n\n\nIran will look to the UNSCR 2231 and JCPOA dates as benchmarks to expand its military modernization. The regime will also seek to distribute some financial gains from the JCPOA to its security forces, although we believe domestic social and economic expenditures will remain the priority for Tehran in the near term.\n\n\n\n…Iran has the region’s largest ballistic missile arsenal, consisting of at least five different systems. Tehran has claimed its missiles can strike targets throughout the region, up to 2,000 kilometers from Iran’s border. Iran will continue to improve the range, lethality, and accuracy of some of those systems and will pursue the development of new systems, despite restrictions placed on development of nuclear capable ballistic missiles by UNSCR 2231. Tehran has claimed it is also pursuing long-range, precision cruise missiles, which will present an increased threat in the region. In addition, Iran maintains the largest underground facility program in the Middle East and primarily uses this capability to protect and conceal many aspects of its missile program. In 2016, Iran publicly unveiled two new short-range ballistic missiles, which Tehran claims are capable of striking targets in a 500-km and 700-km range. Iran will continue to develop space launch vehicles—boosters that are capable of ICBM ranges if configured for that purpose.Stewart summarized developments in North Korea in notably different ways:North Korea is an antagonistic state actor and remains a critical security challenge for the United States. Pyongyang is committed to developing a long-range, nuclear-armed missile that is capable of posing a direct threat to the United States, as demonstrated by two probable nuclear tests and an unprecedented level of ballistic missile launches in 2016. Last year, the North flight-tested over a dozen theater ballistic missiles as well as its submarine-launched ballistic missile system and launched a satellite into space. It also conducted an unusual number of displays in 2016 of its missile programs—including a reentry vehicle heat shield test and ground-level propulsion tests. Earlier this year, North Korea launched what it claimed to be a land-based variant of its submarine-launched ballistic missile and paraded a variety of missiles, including some new systems. More recently, on 13 May, North Korea tested another ballistic missile—successfully launched from western North Korea and impacting in the Sea of Japan. Taken together, these activities highlight Pyongyang’s commitment to diversifying its missile forces and nuclear delivery options while strengthening missile force survivability.\n\n\n\nKim Jong Un views nuclear weapons as the principal tool of regime survival against outside threats—a view underpinned by North Korea’s constitution. In 2016, Kim noted that the main mission of North Korea’s nuclear force was to deter a nuclear war, adding that, “the stronger our nuclear strike capability gets, the more powerful our deterrent to aggression and nuclear war grows.”\n\n\n\nNorth Korea continues efforts to expand its stockpile of weapons-grade fissile material. It claimed that its last nuclear test, in September 2016, was a “standardized” nuclear warhead for a ballistic missile. This test followed its fourth test in early January 2016, after which North Korea issued a statement claiming it had successfully carried out a test of a “hydrogen bomb.” We remain concerned about North Korea’s proliferation activities in contravention of multiple UN Security Council Resolutions including most recently, Resolution 2321 passed in November 2016.But Such Cooperation Is Certainly Possible, Even Probable, at Some LevelIt is hard to believe that either Coates or the director of DIA would omit evidence regarding the level of North Korean and Iranian cooperation, given the Trump Administration’s opposition to the Iran nuclear agreement. At the same time, there are security and policy reasons why they might limit their testimony, and finding hard intelligence on the level of cooperation is extremely difficult—as the lack of any detailed evidence in outside open-source reporting also shows.The politics of arms control and U.S. relations with Iran and North Korea aside, it is extremely hard to determine what level of cooperation exists in nuclear-weapons development—if any—without the kind of rare intelligence breakthrough that provides direct evidence of both the existence and nature of such cooperation. Cooperation in dual-use nuclear technology between two powers that also are developing nuclear power plants can provide critical technology in developing plutonium weapons using the reactor, in developing uranium weapons by creating advanced centrifuges to produce reactor fuel—and both Iran and North Korea have centrifuge facilities.No one can ignore the fact that Iran could now benefit from the fact that North Korea has become a real nuclear power. Once again, there are no detailed official U.S. estimates of its progress. However, David Albright—a widely respected expert on proliferation and president and founder of the Institute for Science and International Security—estimated at the end of 2016 that North Korea’s nuclear programs had reached the following status:• 33 kilograms of separated plutonium (median value of a distribution).• 175-645 kilograms of weapon-grade uranium, where 175 kilograms corresponds to a median estimate for the case of one centrifuge plant and 645 kilograms corresponds to the median estimate for the case of two centrifuge plants.• 13 to 30 nuclear weapons, where these values reflect the utilization of 70 percent of the available, estimated stocks of plutonium and weapon-grade uranium. The limits correspond to the median values for the cases of one or two centrifuge plants and each weapon contains either plutonium or weapon-grade uranium.• Based on this cumulative estimate, North Korea is currently expanding its nuclear weapons at a rate of about three-five weapons per year.• 30 percent of North Korea’s total stocks of plutonium and weapon-grade uranium are assessed as in production pipelines, lost during processing, or held in a reserve.Albright was careful to add a caveat to his estimate, and noted that:The above range of 13-30 nuclear weapons as of the end of 2016, based on the estimates of North Korea’s production and use of plutonium and WGU, is an assessment. … North Korea may have a handful of plutonium-based warheads for its Nodong ballistic missile. … It is unknown if North Korea could mount a warhead on a Nodong that uses only weapon-grade uranium or has a composite core. In particular, are they too large for the Nodong? However, both possibilities appear increasingly likely. … Continued underground testing will provide North Korea opportunities to improve significantly its weapons in terms of less fissile material (particularly plutonium) per weapon, increased warhead miniaturization, and/or greater explosive yields. … Developing thermonuclear weapons, which can achieve all three above goals, is a declared priority of North Korea.\n\n\n\n…It appears capable of developing thermonuclear weapons. It is far more likely to be working on one-stage thermonuclear weapons rather than traditional two stage thermonuclear weapons, or “H-Bombs.” The Institute does not assess North Korea as yet capable of building two stage thermonuclear weapons or utilizing gaseous mixtures of deuterium and tritium in a U.S-style boosted fission weapon. However, North Korea is assessed as able to handle solid forms of lithium-6, deuterium, and/or tritium, such as those used in one-stage thermonuclear weapons or other types of boosted fission weapons.Ongoing cooperation in actual weapons design and production could also be very difficult to detect at some levels. This is a level of progress that could be of immense value to Iran if it ever seeks to break out of the Iran Nuclear Agreement. Moreover, North Korea could benefit from any Iranian lead in centrifuge technology—developments that are not banned by the Iran agreement. It is also possible that it might transfer a weapon for enough money in the future. Albright estimates that it could have enough material for 32-50 plutonium weapons by 2020.Many of the critical components in a nuclear weapon have some dual use, and cooperation in the individual technologies that shape the design and production of nuclear weapons is extraordinarily difficult to detect, characterize, and price. A significant amount of actual nuclear-weapons-design data are now covertly available from third parties, and many of the critical calculations in fluid dynamics and other aspects of weapons designs can also be characterized as dual-use, and covert exchange of such scientific information is extremely difficult to detect.Some key aspects of a nuclear-armed missile—like reentry capability and generic warhead and related technology—can be described as designs for conventional warheads and precision-guided systems, and again involves technology transfers that are difficult to detect and characterize. Some critical aspects of the design of boosted weapons, weapons reliability, and thermonuclear weapons present the same problem.Observing a nuclear test does not provide useful data, but getting the actual data obtained from such tests can be critical in ensuring success and higher yields. A closed society like North Korea can also be a relatively secure place for Iran to carry out simulated explosive tests of weapons designs using non-fissile materials, a host of other directly weapons related tests, and possibly even the test of an Iranian fissile device in ways that again are difficult to detect and have some degree of plausible deniability.Furthermore, official U.S. confirmation of any given form of such cooperation in any detail inevitably discloses U.S. knowledge of Iranian and North Korean progress in nuclear weapons design, production, and deployment. It generally will reveal some aspects of sources and methods. It can disclose important nuclear-weapons data to other proliferators, and it can reveal targeting and arms-control-violation data knowledge.At the same time, simply making generic official statements that nuclear cooperation does exist encourages leaks, congressional and media probing to get the details, international challenges to the statement’s credibility, demands for proof, and outside speculation described as fact. It also can effectively “market” North Korea and Iran as sources of nuclear technology and missiles to other potential proliferators.So, North Korean and Iranian cooperation in nuclear weapons design and manufacture may exist—even at the levels described in the Ofek and Shoham article. The Iran Nuclear Agreement also does potentially give Iran even more reason to seek North Korean assistance in order to hide Iranian weapons efforts. At the same time, it is unclear that any nuclear weapons or proliferating state will give away the “crown jewels” of its nuclear-weapons efforts—particularly given the risk that U.S. and other third-party intelligence services will gain access to them and learn far more about the level of Iranian and/or North Korean progress.Despite all the different (and often conflicting) articles written about such cooperation, the most that can be said is that such cooperation it is certainly possible, and even probable at some level—given the balance of incentives and disincentives. But, Iranian and North Korean cooperation in any form—and particularly at advanced and critical levels—still have to be described as unproven.The Uncertain Evolution of Iranian and North Korean Cooperation in MissilesThere is no such uncertainty about several critical aspects of Iranian and North Korean cooperation in developing and deploying several of the versions of ballistic missiles that have previously been displayed and fielded, even if there is uncertainty as to how cooperation has evolved. Both countries have gone beyond cooperating in the development of short- and medium-range ballistic missiles. They have pursued what seem to be somewhat different paths in developing intermediate-range ballistic missiles that could hit any target in their region, and while North Korea has openly stated that it is developing and will deploy an intercontinental ballistic missile with nuclear warheads that could strike the U.S., there is no similar evidence that Iran is developing such a missile or has an active nuclear-weapons program.Both Iran and North Korea now seem to be pursuing different paths to developing long-range, solid-fuel ballistic missiles, which both need to increase the mobility, concealability, and reliability of their missile forces, and to reduce the problems moving missiles, setting them up for firing, and fueling them—as well as in reaction times, and targetability and vulnerability of their missile forces. Both seem to be pursuing different paths to creating submarine-launched missiles, and both seem to be pursuing different paths to cruise missiles. This does not preclude ongoing cooperation in many aspects of missile development, but the evidence is far less clear and easy to characterize.From the Scud to No Dong and Shahab 3,4The origins of Iranian and North Korean cooperation in developing missile forces date to the 1980s. Iran had to fight Iraq in the bloodiest war in the modern history of the Middle East from 1980 to1988, when it had major problems in obtaining arms imports. Iran did make efforts to revolutionize Iraqi Shiites that helped provoke Saddam’s invasion, but once the fighting started, Iran faced an Iraq that initially had a monopoly on ballistic missiles, had a monopoly on the ability to use poison gas, and was actively seeking nuclear weapons.Iraq began firing Scud and modified Scud missiles at Iran’s major cities, and Iran faced the possibility that Iraq might use missiles with chemical warheads. Iran could not sustain its air force once it broke with the U.S., had no missiles when the war began, and became desperate for some source of missiles to use to retaliate against Iraq.There are no reliable open-source data on exactly how Iran reached out to North Korea (or vice versa), but it is clear North Korea initially had major contracts with Iraq—including building a premature monument to Iraq’s victory in the war. It is also clear that Iran offered enough money to North Korea to turn away from Iraq and—along with Libya—to provide Iran with a supply of Scud B (R-17) missiles.North Korea needed the money and a partner. Again, open-source reporting is uncertain as to the details. Some reports indicate Iran had problems in getting arms from the Former Soviet Union and China, had bought Scud B missiles from Egypt in 1979-1980, and had reverse-engineered a copy and developed a missile-production base that led to test flights in 1984 and actual production in 1985. Less reliable reports indicate that North Korea did get some Scud B missiles from the FSU in the early 1970s, and that the former Soviet Union might have transferred a full Scud production facility. In any case, North Korea had reverse-engineered the Soviet Scud B to create its own version of the missile, which it called the Hwasong, and evidently slowly improved its accuracy, reliability, and range as it acquired more experience in design and production. Estimates differ, but it seems to have had nominal performance of 300 kilometers (184 miles) with a 1,000-kilogram warhead, and a guidance platform theoretically capable of a 400-meter accuracy.Iran initially did not acknowledge that it received Scud Bs from North Korea and Libya during the Iran-Iraq War, but in 2006 did confirm it had done so. It is also clear that Iran was aware that by the late 1980s that North Korea was completing development of a longer-range version of the Scud B/Hwasong—which is generally referred to as the Scud C—with nominal performance of 600-650 kilometers with a 600-750 kilogram warhead, and a guidance platform theoretically capable of a 750-meter accuracy. The new system was tested in 1990 and rushed into some form of initial production in 1991—although it may well have been improved during its relatively long production phase. Iran obtained this missile, and design and production technology from North Korea, and called it Shahab 2.The next key step was North Korean development of a midrange ballistic missile generally called the No Dong (sometimes Rodong), which represented the first North Korean missile that went far beyond modifications of a Scud design and was fully capable of reaching targets in Japan. Development may have begun almost simultaneously with the effort to produce the Scud C, and some reports indicate a variant was tested as early as 1990. However, a successful test did not occur until at least 1993, and there are indications that it was modified in production through 1995.The No Dong was a much larger missile than the Scud, and some reports indicate that its larger engine was designed and produced with Russian commercial aid, as well as aid from Chinese and Ukrainian sources. It may initially have had substantial Iranian financing, and led to closer North Korean-Iranian cooperation in missile-production technology for at least several years. Reports exist of Iranians being present at North Korean test and production facilities.At this point, however, open-source reports on Iranian and North Korean cooperation often conflict. Some sources indicate that Pakistan worked with North Korea during the 1990s to develop a nuclear-armed missile system called the Ghauri, Hatf-5, or Ghauri II. Still other sources indicate that cooperation between North Korea and Iran broke down over financing issues and because of U.S. pressure on North Korea over the nuclear/missile negotiations, and that Iran was forced to design and produce its own variants of the Shahab with help from Russian experts and Chinese companies like Great Wall Industries Corp.—which also began to provide it solid fuel and other key missile technologiesIn any case, Iran took time to produce its own version of a missile very like the No Dong, which it called the Shahab-3 and sometimes the Zelzal-3. Reports on initial performance of the Shahab-3 differ, but it may have a range of between 1,350 and 1,600 kilometers. Estimates of its payload range from 650 to 750, and 1,000 kilograms. Iran did not test its first Shahab missile until 1998, and the test seems to have been a partial success. Iran announced the system was in production in 1999, but other reports indicated that, contrary to other reports about cooperation, Iran had to buy rocket engines from North Korea in 2000. Reports on flight tests in 2000 are conflicting or ambiguous but do not indicate the missile was as yet reliable or particularly accurate.What is clear is that the exact nature of Iranian-North Korean cooperation became increasingly harder to assess with each advance in each country’s missile type and range after the early 1990s, and that Pakistan had also developed some links to North Korea in missile development. Various sources indicate North Korea and Iran developed their own national variants of the basic No Dong and Shahab designs with nominal ranges of well over 1,000 kilometers with smaller payloads, as well as began to actively develop solid-fuel designs.Various reports talk about the possible design and test of much longer versions of Shahab 4 and No Dong B with ranges variously reported at 2,000, 3000, or 4,000 kilometers. Open-source reporting differs over whether versions of the No Dong and Shahab had hardened warheads, simple ABM evasion technologies, cluster munitions, and if chemical/biological warheads were also developed, but again, no reliable open-source data confirms this. In fact, U.S. intelligence sources did not confirm full deployment of the initial No Dong as late as 1998.What is not clear, however, is how much of the post No Dong/Shahab technology was actually shared, how much test and reliability data were shared, and how much warhead data were shared. Similarly, it is unclear which reports of actual cooperation in activities like Iranian and North Korean expert visits and working cooperation are more than rumors. Many are potentially credible, but none seem to have been proved.Open-source estimates of North Korean and Iranian cooperation after the deployment of the initial No Dong and Shahab 3 missiles are often conflicting, and many of the estimates of performance and detailed similarities between systems seem to have been made largely on the basis of missile type, appearance, and size. Other guesstimates about their performance seem to depend on conflicting accounts of missile test firings rather than on the basis of any test data or telemetry. Data on accuracy are generally based on estimates of the optimal accuracy of the guidance platform, without regard to actual missile performance. No open-source data became available on reliability, no hard data were available on warhead types and actual payload size, and no hard data were available on fusing, height of burst, and lethality. Speculation about designing warheads to carry nuclear weapons virtually always is based on warhead shape, not on any evidence as to the actual content of the warhead.The fact remains, however, that Iran and North Korea may well have begun cooperating on space boosters and systems during this period, and were also gaining experience with anti-ship cruise missiles. It is also clear that both countries were developing much-longer-range missiles with higher payloads. These advances in range-payload improved capability to deliver satellites, but also improved their ability to carry conventional and nuclear payloads. There is no meaningful difference between missile bodies that carry “nuclear” and “conventional” payloads, and both countries have a major incentive to develop their own advanced, higher-payload intelligence satellites.North Korea and Iran Move Toward Longer-Range Missiles, Space Systems, and Nuclear WarheadsOpen-source reporting on North Korea and Iran efforts to acquire far longer-range missiles, create a space program, and develop nuclear-armed missiles is even more uncertain, with many conflicting accounts and estimates in various articles. It seems likely, however, that North Korea already had midrange and possibly ICBM design goals by the late 1980s, and saw nuclear weapons as a key way of intimidating South Korea and Japan, giving it leverage over China and countering the U.S. advantage in theater nuclear weapons—as well as eventually giving it the capability to threaten the United States.It seems equally likely that Iran may have begun to at least consider such goals toward the end of the Iran-Iraq war in 1988. Iraq’s use of chemical weapons, and growing knowledge of Iraq’s nuclear and biological weapons ambitions, led Iran’s supreme leader, the Ayatollah Khomeini, to restart the shah’s nuclear-weapons program during the Iran-Iraq War as well as create an active Iranian chemical and biological weapons program.For an Iran then fighting an existential war with Iraq, this again made North Korea a natural ally to the extent that Iran could gain access to North Korea’s longer-range-missile programs and target all of Iraq as well as the Arab state aiding it. For North Korea, Iran again represented a source of dollar income for its hard-pressed economy, a potential additional source of technology and manufacturing experience, and a threat to American interests in the Gulf that put pressure on the U.S. in a different region and complicated U.S. power-projection capabilities and strategic planning.The Taepodong, Unha, Kosar, Shahab 5, and Shahab 6In any case, North Korea’s next key development was the North Korean Taepodong-1 missile, which was North Korea’s first design with the range of an intermediate-range ballistic missile. Various reports indicate it was some 26 meters long, had ranges estimated at 2,000-2,500 kilometers, and payloads estimated at 1,000-1,500 kilograms. The missile was liquid-fueled, like Iran’s previous missiles, but was North Korea’s first major two-stage design. It seems largely to have been a test bed for even larger missiles that could be used to deliver nuclear warheads. It has its first test in August 1998. Some reports give it 1,600-kilometer range, other indicate it may have had a much smaller payload and that fragments of a potential satellite sized payload went 4,000 kilometers.The Taepodong-1 was followed by a much larger version—generally called the Taepodong-2—that had the potential range payload to grow into an ICBM that could potentially deliver a nuclear weapon against some part of the U.S. Again, reports differ, but it seems to have been around 32 meters long, had a three-stage liquid fuel system with a much larger booster, and a range of 4,000-6,700 kilometers depending on payload.The Taepodong-1 seems to have been designed primarily for satellite launches, although all of its technology helped North Korea move toward much-longer missile ranges. Its first test was in 2006 and was a failure. Variants called the Unha failed to launch satellites in 2009 and 2012, but it did succeed in launching one later in 2012 and again in 2016. It is important to note, however, that the Taepodong requires major support facilities, a large fixed launch pad, and takes days to fuel. It provides lessons for the development of an IRBM and ICBM but is scarcely a good military platform for quick-reaction launches and concealment of a missile force.North Korea may have sold at least some of the technology for the Taepodong to Iran and Pakistan. One report indicates North Korea made sale of the technology and possibly elements of the missile available to Iran in 2004. In any case, Iran developed its own long-range missile, which various countries and articles label as the Shahab 5, Shahab 6, and Kosar. Reports have given the Shahab 5/Kosar ranges of 3,500-3,750 kilometers with a 1,000-750-kilogram warhead, and given the Shahab 6 a range of 4,000-4,300 kilometers with the same warhead. Like the Taepodong, accuracy is likely to be limited, and a military version would need a nuclear weapon to reliably hit and damage even a city-size target.The level of cooperation between North Korea and Iran in developing such advanced systems remains uncertain. Some reports indicate the Kosar/Shahab 5/Shahab 6 uses the same booster as the Taepodong. Other sources indicate North Korea sold Iran booster engines. Sttill other reports indicate that the Iranian missile used different Russian engine designs from the physically similar North Korean missile.Michael Elleman, consulting senior fellow for missile defense at the International Institute for Strategic Studies, a U.K.-based think tank, summarizes these uncertainties as follows,…many observers note the similarity between the satellite-launch vehicles, or SLVs, used by Iran and North Korea, and speculate that the two countries are collaborating on large rocket development. It is true that the Taepodong-1 SLV launched by Pyongyang in 1998, and Iran’s Safir SLV have first stages powered by the Nodong engine. It is also true that the first stage of the North Korea’s Unha SLV and Iran’s Simorgh SLV use a cluster of four-Nodong engines, and the upper-most stages of both SLVs are propelled by the steering engines originally employed by the now-retired Soviet R-27 SLBM.\n\n\n\nBut a closer look at the SLVs reveals differences inconsistent with close cooperation between Pyongyang and Tehran. The most obvious difference is that the two North Korean SLVs operate using three stages, whereas Iran’s two SLVs are two-stage systems. This likely reflects the more conservative design approach taken by North Korea, where until late-2015, engineers had limited experience developing new missiles and launchers. The paucity of missile-development testing, and learned knowledge accrued from testing activities, likely led North Korean specialists to over-design the Taepodong-1 and Unha launchers to ensure each succeeded in lofting a specified payload to a certain orbit. There may, however, be other reasons behind the decision to employ three rather than two stages. Regardless, the divergent design philosophies argue against deep cooperation.One key point, however, is that relying on very large, complex multistage liquid-fuel missiles presents the same problems in setup and reaction time, reliability, and targetability for both countries. They are far less desirable for military applications compared with more modern, cheaper and smaller alternatives—especially solid-fuel missiles—although the large liquid-fuel boosters have broad value for space launches. Smaller, cheaper, and generally more mobile and reliable missile systems can be used to attack all neighboring and more in-theater targets, and shifting to solid fuels reduces setup and reaction time, size and mobility/concealment problems, reliability problems, and costs.The Uncertain Nature of current and Future Cooperation in Missile Technology and ProductionFrom roughly the later 1990s onward, North Korea and Iran had common incentives to examine other missile technologies and designs, including solid-fuel missiles, precision-guided conventional missiles, and cruise missiles, along with countermeasures to ballistic-missile defenses, which both need to increase their mobility, concealability, and reliability of their missile forces, and to reduce their setup, reaction times, targetability, and vulnerability. Both countries, however, seem to be pursuing different paths to creating submarine-launched missiles, and both seem to be pursuing different paths to cruise missiles. Both countries also seem to have different access to Russian and Chinese technology and supply sources, although experts outside the intelligence community debate all of these issues.Iran does seem to have had less strategic incentive to seek a nuclear-armed ICBM than North Korea, although this might change if it attempted a nuclear breakout and sought to more directly deter the United States. North Korea has faced direct nuclear threats and has had reason to find some way of posing a similar direct threat to the United States. The U.S. openly deployed tactical and theater nuclear weapons in South Korea until 1991, and the U.S. still has a de facto commitment to providing South Korea with “extended deterrence” that could involve the deployment of U.S. nuclear weapons. This helps explain why North Korea has openly committed itself to developing and deploying nuclear weapons, and has made efforts to acquire nuclear weapons and develop a nuclear-armed ICBM threat against the United States. It also can do so with less risk of provoking its neighbors into their own forms of nuclear proliferation. South Korea and Japan are very different political cases from Israel and the Arab states.As became all too clear in 2016 and 2017, a nuclear-armed ICBM threat (and potentially a submarine-launched missile threat) has become a key overt part of North Korea’s strategy. A nuclear-armed-missile threat gives North Korea far more credibility in direct confrontation with South Korea, Japan, and the U.S. Dispersed solid-fuel ICBM and IRBMs, and submarine-basing of its nuclear missiles make it far harder for the U.S. to detect and target North Korean forces and conduct any kind of first strike against it. Moreover, North Korea may well calculate that threats or use of such nuclear-armed systems would also act as a “trigger force” that could push China into becoming involved on North Korea’s side, giving it added leverage over both China and the U.S.In contrast, Iran has never faced a direct nuclear threat from the U.S. and has little incentive to provoke one, increase the nuclear threat from Israel, or push its Arab neighbors into acquiring their own nuclear weapons. Iran can use much-shorter-range precision-guided and conventionally-armed missiles to strike at critical petroleum, military, desalination, electric generation, and fixed military targets throughout the Gulf, and threaten Gulf cities and population centers as well.Moreover, once Iran develops conventionally-armed precision-guided missiles, it can fire mixed volleys of precision-guided and older missile systems to try to saturate U.S. and Gulf missile defenses. Precision-guided missiles can allow Iran to shift from “weapons of mass destruction” to “weapons of mass effectiveness. An Iranian focus on conventionally-armed missiles has not provoked the same kind of worldwide opposition and sanctions as its efforts to acquire nuclear weapons and does not drive its neighbors to proliferate.This different set of strategic conditions does not mean that Iran is not seeking nuclear-armed missiles or ICBMs, or preclude ongoing cooperation in many aspects of missile development. Iran may still see a reason for a covert ICBM program and at least a contingency capability to deliver nuclear warheads. But it does mean that North Korean and Iranian interests are less identical than at the point when their missile cooperation began. That, combined with the wider range of options each state has to develop its full range of missiles, helps explain why evidence regarding their current level of cooperation is less clear and difficult to characterize.Current Indications Regarding Iranian and North Korean Missile CooperationAs is the case with nuclear weapons, there are a great many, often conflicting, open-source reports about the current state of Iranian and North Korean cooperation. One striking area where cooperation may have continued is in the development of a large 80-ton booster that can be used for both satellite launches and long-range missiles. The U.S. State Department formally sanctioned the Iranian Shahid Hemmat Industrial Group (SHIG) and two of its employees for working with North Korea in “the development of the 80-ton rocket booster.” It is unclear whether the 80-ton figure referred to an entire missile or an 80-ton engine—although North Korea has tested an engine that size and one that may be a version of the Chinese YF-20.At the same time, such reports about Iran’s ties to North Korea must be kept in perspective. It is also clear that Chinese commercial agents and companies, as well as their Russian equivalents, are other major sources of missile technology. The U.S. Treasury provided the following description of the role Chinese companies played in Iran’s missile programs in sanctions that it issued in February:Today, the U.S. Department of the Treasury’s Office of Foreign Assets Control (OFAC) sanctioned multiple entities and individuals involved in procuring technology and/or materials to support Iran’s ballistic missile program, as well as for acting for or on behalf of, or providing support to, Iran’s Islamic Revolutionary Guard Corps-Qods Force (IRGC-QF). … This action reflects the United States’ commitment to enforcing sanctions on Iran with respect to its ballistic missile program and destabilizing activities in the region and is fully consistent with the United States’ commitments under the Joint Comprehensive Plan of Action (JCPOA).\n\n\n\nMore specifically: OFAC designated several networks and supporters of Iran’s ballistic missile procurement, including a critical Iranian procurement agent and eight individuals and entities in his Iran- and China-based network, an Iranian procurement company and its Gulf-based network, and five individuals and entities that are part of an Iran-based procurement network connected to Mabrooka Trading, which was designated on January 17, 2016. This action was taken pursuant to Executive Order (E.O.) 13382, which targets proliferators of weapons of mass destruction and their means of delivery and supporters of such activity.\n\n\n\n…Iran’s continued support for terrorism and development of its ballistic missile program poses a threat to the region, to our partners worldwide, and to the United States. Today’s action is part of Treasury’s ongoing efforts to counter Iranian malign activity abroad that is outside the scope of the JCPOA,” said Acting OFAC Director John E. Smith. “We will continue to actively apply all available tools, including financial sanctions, to address this behavior.North Korean DevelopmentsAt the same time, other work by Michael Elleman notes that North Korea may have increased its dependence on Iran in its efforts to develop solid-fuel rocket motors—although there are differences between the two major North Korean and Iranian missiles that are most likely to be involved—the Iranian Sajji/Ashora and the North Korean KN-11 (variants of which are designated the KN-15):Iran, unlike North Korea, has pursued both liquid- and solid-fueled missiles since its dual-track approach to missile acquisition started in the early 1980s. Iran now possesses a family of short-range missiles, including the Fateh-110 and Fateh-313, which were developed over a period of at least two dozen years. Tehran is also developing a two-stage, medium-range missile, the Sajjil. The Sajjil program likely began in or about the year 2000. The first ground tests of the 13.5-metric ton, stage-one motor reportedly occurred in 2005. The Sajjil, though dubbed Ashoura at the time, underwent its initial flight test, which failed, in 2007; a successful test occurred in 2008, though only the first stage was active. Flight-testing continued until 2011, when launches abruptly stopped before the missile was fully developed. The reasons behind the halt in testing remain unclear.\n\n\n\nNorth Korea, on the other hand, has limited experience developing and producing solid-fueled missiles. The largest solid-rocket motor manufactured by Pyongyang before 2016 weighs only one-metric ton and propels the KN-02 missile, a copy of the Soviet Tochka. The KN-02 has a maximum range of about 100 km, though versions of the original Tochka can reach beyond 120 km. In April 2016, North Korea conducted a ground test of a large solid fueled motor and test launched at least two solid-propellant missiles from an underwater platform, likely its GORAE-class submarine. The KN-11, submarine-launched ballistic missile (SLBM) is a two-stage system. Each stage consists of a solid-propellant rocket motor substantially larger than any tested by the North before, excepting the April ground test. Learning to manufacture large-diameter, solid-fueled rocket motors typically requires decades of effort, as illustrated by the history of Iran’s program, as well as others. Yet, with no public reporting of large solid-motor development in North Korea prior to 2016, the KN-11 emerged suddenly and flies successfully to a distance of 500-600 km.\n\n\n\nThe sudden, unexpected appearance of the solid-fueled KN-11 led to speculation that Iran may have aided Pyongyang’s efforts to design, develop and manufacture large-rocket motors, or perhaps supplied the motors to North Korea outright. Tal Inbar, an Israeli analyst who closely follows the missile and space programs of Iran and North Korea, asserts that the KN-11’s 1.25 m diameter motors are the same as those found on Iran’s Sajjil missile. He further states that the KN-11 is built using a propellant that is “identical to the technology developed in Iran.Elleman concludes that the two missiles are too physically different to use the same rocket motor, and if North Korea is really seeking to deploy a submarine-launched ballistic missile, Iran also lacks a current capability to build its own submarines and probably cannot modify its Russian Kilo class submarines to deck-mount a large ballistic-missile launcher. If Iran is supplying solid-fuel data to North Korea—and/or obtaining large rocket motor or booster data from North Korea for its satellites—this may well indicate that their cooperation is entering a different phase—one in which Iran’s efforts are harder to tie to any Iranian ICBM or nuclear program.The KN-15 is reported to be a two-stage solid-fuel missile and may be identical to—or very similar to—the one referred to by Elleman. While the missile is variously estimated to have a range of 1,200 to 5,500 kilometers, and seems to be designed to carry a nuclear warhead, it flew 500 kilometers before landing in the East Sea. However, it also reached an altitude of 550 km (340 miles) and may have been carried out to test warhead-entry capability. The same missile also had another high apogee test May 21, which would have given it a normal trajectory range of some 1,250 kilometers. (To put these ranges in perspective, this would reach targets in Japan and South Korea, but U.S. bases in Guam are some 3,200 kilometers from North Korea).The KN-15 (11? 17?) is variously described as a transporter-erector-launcher-based missile, which is the most probable way Iran would base and use such a missile, while other sources like the South Korean JCS have previously reported that the DPRK Naval Strategic Rocket Forces successfully tested a Pukgukong SLBM on Aug. 24, 2016. Still other reports suggest there may be a land-based Pukguksong-2 and a Pukguksong-1 sea-launched variant, again illustrating the uncertainties in the reporting on one country’s developments, which further complicate any reporting on both.North Korea also continued to openly moved toward developing nuclear-armed ICBMs and openly threaten the U.S. and the region with nuclear war—threats it openly began making in 2015. It conducted an exceptionally high number of missile tests after President Trump’s inauguration—nine tests or groups of tests by the end of May. Some tests were political—one occurred Jan. 12, just two days before a U.S.-Chinese Summit meeting, and seems to have been a KN-15 or Pukguksong-2 medium-range missile. Others were part of its effort to develop other reliable longer-range missiles. North Korea also may have tested a Musudan IRBM on March 21. The missile exploded within seconds of launch, however, and this marked another test failure for a missile that North Korea had conducted eight test-firings of in 2016, with only one success.North Korea displayed some 15 missiles at an annual military parade April 15, including three canisters or missiles that seemed to be designed to show it was developing nuclear-armed ICBMs, although they may have been showpieces rather than real-world designs. One missile canister was large enough to hold a KN-08, or Hwasong-13. This is a design said to be a three-stage missile with a theoretical range of about 7,500 miles. Another was large enough to have held the equivalent of the Russian Topol-M. North Korea also displayed a black-and-white missile that was potentially of ICBM size that also could have been a KN-08, although it was mounted on a smaller missile vehicle designed for the medium-range Musudan missile.Iranian DevelopmentsIn contrast, Iran has conducted far fewer long-range tests, made no nuclear threats, and has seemed to focus on developing precision-guided weapons—including a precision-guided and upgraded version of the Shahab 3 called the Emad, and cruise missiles like the Soumar—that would make conventional warheads effective against point targets in the Gulf and at ranges that could include Israel, Turkey, all of Saudi Arabia, and possibly Europe.Iran has rejected UN resolutions 1929 and 2231, which call for it to halt all missile tests that have the range payload to carry a nuclear weapon and any effort to link them to the Iran Nuclear Agreement. Iranian Foreign Minister Mohammad Javad Zarif stated on Jan. 31 that these UN resolutions were not part of the Iran Nuclear Agreement; would deprive it of the ability to fire all or general significant ballistic missiles regardless of whether that had a conventional warhead, a key counterbalance to the superior air forces in the Arab Gulf states; and that the U.S., Britain, and France can project into the Gulf region. He also again denied that Iran was seeking a nuclear weapon.Iran has rejected U.S. pressure to halt its missile tests, and conducted its first MRBM test of 2017 on Jan. 29—sending a clear signal to the Trump administration. It then conducted tests in early February after the Trump administration imposed sanctions in reaction to Iran’s first test. It also launched two more missile tests—including what seems to have been a precision-guided anti-ship version of the Fateh 110 SRBM—on March 5. This seems to have marked the 14th set of Iranian missile tests since the Iran Nuclear Agreement was signed in July 2015, although accounts differ in detail.However, Iran has never declared that it is developing an ICBM or a capability to target U.S. The most it has done is to have officers like Brig. Gen. Seyyed Mehdi Farahi, an officer in the Revolutionary Guards Corps, then the managing director of Iran’s Defense Industries Organization, who seems to have stated in 2010 that Iran had the technological ability to target any point on the planet with an intercontinental ballistic missile should it so choose.The Prospects for On-Going North Korean and Iranian Cooperation in MissilesIran may still be pursuing its nuclear ambitions at some covert level and working with North Korea, and may have a covert ICBM program that it continued to develop under the guise of creating space boosters and in coordination with North Korea. There is no publicly available hard evidence of such efforts, however, and the two nations may now be cooperating largely on a transactional basis, trading technologies, test data, key components, and other elements of different indigenous missile programs.It is possible, for example, that covertly trading test data would allow both countries to reduce the risks posed by their individual test programs or accelerate their programs at the same level of risk. North Korea may be in a position to sell re-entry and advanced warhead technology before Iran can develop it. Iran may have the advantage in precision-guidance technology, and both countries might gain in trading solid-fuel-motor technology, cruise missile, anti-missile technology, and other types of warhead data. At a lower level, they might exchange missile transporter-erector-launcher and missile-carrier data, as well as deployment, concealment, shelter methods, and technology.The relative need each country has for such exchanges of technology is unclear. In the past, many experts felt Iran had a clear lead in solid-fuel technology over North Korea, but the previous reporting shows that North Korea did much to demonstrate longer-range solid-fuel missiles in 2016 and 2017, and that showed it had competing development efforts in such programs. In late May, it was also North Korea that made ambitious claims regarding precision guidance for its longer-range missiles, claiming it had launched a Scud-like missile on May 29 that had “advanced automated prelaunch sequence” to reduce its reaction time and exposure to attack, was mounted on a TEL, and had a new type of precision–guidance system that flew 400 kilometers and whose warhead struck only 7 meters from its target. Given these uncertainties, it is hard to make even broad estimates of which nation needs the other more in any given area of missile technology.At the same time, recent U.S. sanctions and a wide range of reporting indicate that Iran and North Korea may be making such trades and sales as part of a broad cooperation effort with other powers. Rather than focusing on bilateral efforts, they may be making deals involving Pakistan, Chinese agents and companies, Russian technical experts and companies, and engaging in covert purchasing efforts in the U.S. and Europe. In short, it seems highly likely that Iranian and North Korean cooperation continues at some level, but it is far harder to characterize than in the past, and there are no recent intelligence reports or leaks that provide a firm foundation for estimating the actual level of cooperation between them.***Read more from Tablet’s special Iran Week.