For more than 50 years, Israel’s national security has been guided by the Begin Doctrine, named after the country’s sixth prime minister. It holds that no regional enemy committed to destroying the Jewish state can be allowed to obtain weapons of mass destruction. To that end, Israel’s air force destroyed Iraq’s Osirak nuclear reactor in 1981 and Syria’s al Kibar plutonium-producing facility in 2007.Today’s cascade of nuclear technologies across the Middle East, however, is raising serious questions about Israel’s ability to enforce this mandate going forward. The debate over the Begin Doctrine’s viability will not only have a profound impact on Israel, but also on security in the broader Middle East. Israel has proven more than once to be the only regional player willing to curtail by force the spread of nuclear weapons to rogue states, despite the international opprobrium the Jewish state has reaped for its actions. But current concerns inside Israel reflect just how much the threat of nuclear proliferation has increased in recent years as the countries of the Middle East have changed and transformed the region.Israel views Iran as by far the most likely regional power to acquire nuclear weapons in the near term and has openly vowed to use military force to stop it. But a slew of other Mideast countries, some nominally Israel’s allies or strategic partners, have also made significant advances in their nuclear programs. Turkish President Recep Tayyip Erdogan openly warned in September that Ankara could seek to develop atomic weapons in response to its changing relationship with the U.S. and the North Atlantic Treaty Organization. Saudi Arabia’s crown prince and de facto leader, Mohammed bin Salman, has said his country would match any nuclear technologies that Iran, Riyadh’s arch rival, acquires.Israeli officials and analysts say that, as a result of these evolving threats, the tools required to enforce the Begin Doctrine will need to change. Israel deployed cyber weapons, in collaboration with the U.S., to attack Iran’s uranium-enrichment facilities in the late 2000s. The operation destroyed thousands of centrifuge machines, but Tehran’s overall nuclear-fuel production quickly returned to pace. Israel also signed on to the U.S. sanctions campaign that has used financial warfare to pressure Iran into giving up or constraining its nuclear activities. The strategy helped birth the 2015 Joint Comprehensive Plan of Action—the Obama-helmed Iran nuclear agreement between Tehran and world powers, which President Donald Trump pulled out of last year with the backing of Israeli Prime Minister Benjamin Netanyahu. Both leaders believed the deal offered, at best, only a short-term solution to the Iranian nuclear threat while forfeiting the sources of economic leverage that may have forced Iran to accept more permanent restraints.But the standard tools of economic and military coercion, even including the high tech instruments of cyberwar, might not be enough any longer to prevent nuclear proliferation in the Middle East as countries like Turkey and Saudi Arabia—both official U.S. strategic allies—grow their own nuclear programs. Israel has diplomatic relations with Turkey, which remains an active member of NATO and houses 50 American nuclear weapons at the U.S. military base in Incirlik. But the Israeli-Turkish relationship has been strained under Erdogan’s Islamist government and by conflicting approaches to the Syrian civil war on their respective borders. Israel has also developed a strategic partnership with Saudi Arabia, with the on-and-off foes, united by a common enemy, now sharing intelligence and technology to try and constrain Iran’s regional activities.The Trump administration is currently negotiating a nuclear-cooperation agreement with Mohammed bin Salman’s government that could allow the Saudis to develop sensitive nuclear technologies, such as uranium-enrichment and plutonium reprocessing, in exchange for Riyadh accepting expansive international oversight of its program to prevent the nuclear program from being weaponized. But whatever the technical terms are in a prospective agreement, there’s still no guarantee Saudi Arabia won’t seek to develop weapons at some stage or that the ruling Saud family will remain in power.“The Begin Doctrine has to be somewhat rephrased: ‘Israel will do its utmost to prevent, or at least delay, any hostile Middle East country from obtaining a military nuclear capability,’” says Ephraim Asculai, a 40-year veteran of the Israel Atomic Energy Commission. “The means of prevention would vary from diplomatic and treaty diplomacy to covert, low-key sabotage, to open overt military action, if possible, depending on the regional politics at the time. Success cannot be really assured, but the effort should be made.”\n***\nIran’s announcement in November that it’s resuming uranium enrichment at its Fordow underground nuclear facility has alarmed the Israeli security establishment. The Netanyahu government vehemently opposed the nuclear deal, known as the JCPOA, stressing that it was only a temporary obstacle to Tehran’s nuclear ambitions. But some Israeli officials had hoped the accord could keep the Iranian nuclear program in check long enough for U.S. and European diplomats to strengthen the deal’s core elements through a renegotiation with Iran.One of the JCPOA’s core tenets was that Iran’s stockpile of nuclear fuel would be kept below the levels required for the country to build a single atomic bomb within a year. But with the resumption of enrichment at Fordow, Israeli and American nuclear analysts believe this timeline has already shrunk to between six and 10 months. Meanwhile, Iran has also begun enriching uranium at levels closer to weapons grade.This heightened nuclear threat comes after Iran has spent years developing Syria as a base of operations to launch drone and missile strikes against Israel. Israeli officials believe Tehran is consolidating a “ring of fire” around the Jewish state’s borders by arming and funding militias in Syria, Lebanon, the Palestinian territories, Iraq, and Yemen. In response, Israel has repeatedly bombed Iranian proxies in recent months in Syria and as far away as Iraq, and is hoping the Trump administration’s financial campaign of “maximum pressure” will force more far-reaching nuclear concessions from Tehran down the road. There’s some hope as well that Iran is weakening from within after weeks of nationwide protests driven by the government’s slashing of energy subsidies.These are happening at the same time that political uprisings have erupted in Iraq and Lebanon driven, in part, by opposition to Iran’s overweening political and military influence in those Arab countries.Still, current and former Israeli officials are skeptical Iran can be brought back to the negotiating table. And they voice concern that Tehran is sequencing the renewed growth of its nuclear program with the extension of its proxy network to Israel’s borders. This in turn is prompting warnings from Israel’s national security establishment that it’s prepared to strike Iran directly to enforce the Begin Doctrine. “If we have to do it again, we’ll do it again,” Yaakov Amidror, a retired general and Netanyahu’s former national security adviser, said at a recent security conference in Tel Aviv, referring to Israel’s earlier attacks on Iraq’s and Syria’s nuclear installations.\n***\nNuclear threats from Turkey’s President Erdogan have also caught Israel’s attention in recent months. Speaking to members of the ruling AK Party in September, he warned that it was unacceptable that Turkey couldn’t develop nuclear weapons when so many of the world’s great powers had them or possessed the technologies to build them. Israel is believed to have a large atomic weapons arsenal, but has never confirmed or denied its existence. “Some countries have missiles with nuclear warheads, not one or two. But [they tell us] we can’t have them. This, I cannot accept,” Erdogan told a conference in eastern Turkey, Reuters reported. He added: “We have Israel nearby, as almost neighbors. They scare [other nations] by possessing these. No one can touch them.”Turkey has been pursuing civilian nuclear power for decades, and broke ground on its first reactor, which is being built by Russian companies, last year. Israel hasn’t publicly voiced alarm about Turkey’s nuclear ambitions to date, because the country has historically been an ally and has pledged its adherence to the Nuclear Nonproliferation Treaty, or NPT, the United Nations covenant that bans the development of atomic bombs by countries others than the five original nuclear weapons states. Ankara, as a NATO member, also is protected by the nuclear umbrella provided by the U.S.But Turkey’s future NATO membership, and its alliance with the U.S., has grown increasingly unstable in recent years as Erdogan has shown a greater willingness to challenge, if not break, from the West’s foreign policy objectives. Erdogan’s decision in September to invade northern Syria, and assault the Kurdish forces there, was staunchly opposed by the U.S. Defense Department and ran the risk of sparking a direct confrontation between Turkish and American troops. Some members of Congress are now calling for economic sanctions on Ankara and the removal of the American nuclear weapons deployed at Incirlik. Relations between Israel and Turkey have also sharply deteriorated in recent years, as Erdogan has positioned himself as a champion of the Palestinian cause and an ally of Iran.In this environment, Israeli officials and analysts are concerned that Erdogan might make good on his rumblings to develop nuclear bombs as he continues to lead his country away from the West. Even before his September nuclear pronouncements, Turkey had repeatedly rebuffed Western calls for it to rule out developing the capability to enrich uranium or reprocess plutonium, the key technologies for weapons development. Ankara’s nuclear cooperation with Moscow also limits the West’s ability to use diplomatic or economic pressure to constrain Turkey’s nuclear ambitions. Military threats or sabotage to enforce the Begin Doctrine, Israeli analysts acknowledge, are less effective against a country as developed as Turkey and as integrated into the global economy. Turkey’s not isolated, or viewed as a rogue state, like Saddam Hussein’s Iraq, the Assad family’s Syria, or the Islamic Republic of Iran. Which leaves the question, if the old policy no longer works, what exactly can be done?***Saudi Arabia’s nuclear advancements pose perhaps the most delicate proliferation challenge for Israel and the Begin Doctrine. For most of the Jewish state’s history, Riyadh was viewed as a foe due to its support for the Palestinian cause and exporting of its fundamentalist brand of Islam, known as Wahhabism. Saudi Arabia sent troops to fight Israeli forces during the 1973 Yom Kippur war and used oil as a weapon against those countries that supported the Jewish state during the conflict.But relations between Israel and Saudi Arabia have improved dramatically over the past five years, driven, in large part, by their shared focus on the Iranian threat. The two countries have yet to formally normalize diplomatic relations. But they’re sharing intelligence and technology to try and constrain Tehran, according to Israeli and Arab officials, including by tracking Iranian activities in Yemen and the Red Sea. Israeli diplomats are now openly visiting Saudi Arabia’s allies in the Persian Gulf, Bahrain and the United Arab Emirates, in what’s widely viewed as a precursor for more overt Israeli-Saudi contacts.Saudi Arabia, with an eye on Iran’s nuclear ambitions, has been developing its own program. Crown Prince Mohammed bin Salman last year bluntly proclaimed his country was committed to acquiring whatever nuclear technologies Tehran does. The Saudi government has embarked on an ambitious effort to construct 16 nuclear power reactors over the next 20 years, and is currently finishing the construction of a research reactor with Argentine help. “Saudi does not want to acquire any nuclear bomb, but without a doubt, if Iran develops a nuclear bomb, we will follow suit as soon as possible,” Crown Prince Mohammed told CBS News last year.Despite the improving relations between the two countries, Israeli officials are still worried about Saudi Arabia acquiring nuclear capabilities—as they are with all of the regional powers. But as in the case with Turkey, the tools to deter the House of Saud are seen as limited. Few in Israel believe military action or sabotage can be used against Riyadh. And Israel hasn’t sought to rally congressional opposition in Washington against the Saudi program, mindful of the close U.S. alliance and its own improving relations with the kingdom.The Netanyahu government, instead, has been backing a Trump administration proposal to overtly share nuclear technology with Riyadh in exchange for Saudi Arabia backing away from plans to acquire uranium-enrichment and plutonium-separation technologies. Outgoing U.S. Energy Secretary Rick Perry has been holding negotiations with Saudi officials to forge a formal nuclear-cooperation agreement based on this “gold standard.” But it’s unclear if the Saudis will accept the terms, and Riyadh has concurrently been discussing purchasing reactors from Russia, China, and South Korea as a way to work around American pressure.U.S. and Israeli officials are also concerned that Saudi Arabia could simply buy nuclear weapons from Pakistan should the conflict with Iran intensify. Riyadh is believed to be the primary financier of Islamabad’s so-called Sunni Bomb and also provides substantial energy support to the South Asian country. Pakistani troops, in turn, have been deployed to Saudi Arabia to help enforce security. “In a scenario of an Iranian breakout to a nuclear weapon, the Pakistani commitment to maintain the Kingdom’s security could be expressed through the transfer of nuclear warheads…or the stationing of nuclear weapons,” writes Israeli security analyst Yoel Guzansky of the Institute for National Security Studies in Tel Aviv.Israel’s national security establishment, though, views Iran as the fulcrum through which to try and stanch the cascading spread of nuclear weapons across the Mideast. Permanently constraining Tehran’s capability, they argue, will drastically reduce the desire of Turkey, Saudi Arabia, and even Egypt, to militarize their nuclear power programs. If Iran, however, becomes a threshold weapons state, which it was on track to do even under the JPCOA, Israel and the West will have diminishing tools to reverse this course. A campaign of cyber warfare, supply-chain sabotage and economic sanctions may be in the works. But there’s no guarantee they’ll work, and the Begin Doctrine could be rolled back.***Like this article? Sign up for our Daily Digest to get Tablet magazine’s new content in your inbox each morning.