As the June 30 deadline for striking a comprehensive nuclear deal with Iran looms, discussions quickly get bogged down in debates about numbers and types of centrifuges, schedules for sanctions relief, and procedures for international inspections. These arcane issues cause many people’s eyes to glaze over, but, in reality, the details of the ongoing negotiations are acutely irrelevant to the merits of the deal that the Obama Administration wants to strike.Indeed, one can assess the merits of the outlined nuclear deal without any reference whatsoever to its finer points. The framework deal does not even come close to qualifying as an acceptable nuclear agreement, and the reason is simple and easy to understand: Since the beginning of the nuclear era, scientists have understood that the exact same technology could be used to produce fuel either for nuclear energy or for nuclear weapons. The two methods for producing nuclear fuel, uranium enrichment and plutonium reprocessing, therefore, became known as “sensitive nuclear technologies.” The United States has always opposed the spread of sensitive nuclear technologies to all states, including its own allies, and it should not make an exception for Iran.I personally worked on nuclear issues both in and out of government (including at the Pentagon and other agencies) for over a decade, and I and many of my colleagues had always assumed that the only way to prevent nuclear proliferation in Iran would be to eliminate its uranium enrichment capability. For over a decade, U.S. policy reflected this assessment. Throughout the 2000s, the Bush Administration engaged in international negotiations with Iran, but its bottom line never changed: The only deal worth having was one that stopped enrichment in Iran. Senator and U.S. presidential candidate Barack Obama also supported this goal, saying at a 2007 meeting of AIPAC, “The world must work to stop Iran’s uranium-enrichment program.”The policy that both Democratic and Republican presidents and presidential candidates have supported for the past seven decades is a sensible compromise that encourages the peaceful uses of nuclear technology while managing its proliferation dangers: Countries can operate nuclear reactors for power or research purposes, but they are not permitted to make their own fuel. The vast majority of countries on Earth with nuclear programs do not possess sensitive nuclear facilities. Rather the fuel is provided by a more advanced nuclear power, such as Russia, France, or the United States. This eliminates the need for the spread of dangerous enrichment or reprocessing programs to new countries. Countries like Iran that insist on developing their own sensitive technologies for “peaceful purposes,” therefore, are tipping their hand and revealing a likely intention to build the bomb.To stop determined proliferators, the United States and the rest of the international community have worked hard to halt the spread of enrichment and reprocessing technologies, a campaign that has been prosecuted with equal vigor by Democratic and Republican administrations alike. The enforcement of this policy began even before nuclear weapons were invented, when Norwegian saboteurs and allied bombing runs knocked out a heavy-water production facility necessary for the plutonium path to the bomb (and similar to Iran’s heavy-water production facility under construction at Arak) located in Nazi-occupied Norway. It continued after World War II as the United States tried to prevent the leaking of dangerous nuclear know-how. In 1946, the U.S. Congress passed the McMahon Act, which made it illegal for the United States to cooperate with any country, including its closest allies, on sensitive nuclear technologies. Even countries that had worked with the United States to invent the bomb at the Manhattan project, like Canada and Great Britain, were cut off.Several advanced industrial countries, including Britain, France, Germany, and the Netherlands, were able to develop sensitive nuclear technologies early in the nuclear era without Washington’s assistance, but this only reinforced the United States’ understanding about the potential dangers of these dual-use nuclear technologies.When America’s Cold War adversaries, the Soviet Union and China, began enrichment and reprocessing programs, the United States immediately interpreted these as the building blocks of a nuclear weapons program, and high-level U.S. decision makers seriously considered military strikes against these facilities to keep these countries from the bomb. (In the end, they refrained only because they feared starting a superpower war, something that has not been a concern since the Soviet Union’s collapse in 1989.)Not even Israel, America’s longstanding security partner, was spared from America’s deep commitment to nonproliferation. When the U.S. government suspected that Israel was building a secret reprocessing plant beneath its reactor at Dimona in the early 1960s, U.S. President John F. Kennedy demanded that Israel allow inspectors on the site. Kennedy wrote a letter to Israeli Prime Minister David Ben-Gurion, threatening that if Israel were not more forthcoming about an issue as important to international security as the possible existence of a secret plutonium reprocessing plant, then “America’s deep commitment to the security of Israel” could be “jeopardized.”The United States soon understood that it would need a multilateral framework for managing the spread of nuclear weapons, and in 1968 it led the negotiations of the Nuclear Nonproliferation Treaty (NPT). All nonnuclear weapon state signatories, including Iran, agreed never to build nuclear weapons in exchange for several benefits, including the “inalienable right to peaceful nuclear technology.” Iran insists that this treaty grants it a “right to enrich,” but the NPT does not explicitly mention uranium enrichment, and the United States has never interpreted Article IV as providing an inalienable right to sensitive nuclear technologies.To further strengthen multilateral bulwarks against the spread of sensitive nuclear technologies, then-U.S. Secretary of State Henry Kissinger spearheaded the creation of the Nuclear Suppliers Group in 1975. This international cartel of capable nuclear supplier states places tough restrictions on the transfer of uranium enrichment and plutonium reprocessing technologies.The strength of the United States’ nonproliferation approach can be seen in the vast majority of countries that never attempted to develop sensitive nuclear technologies, but when these measures were not enough, Washington went to work on a case-by-case basis to put an end to sensitive nuclear programs, even taking the gloves off in standoffs with friends. In 1975, when Germany planned to build enrichment and reprocessing plants for Brazil in the so-called nuclear “deal of the century,” Washington intervened to slow and eventually kill the deal. In the late 1970s, it also convinced France to cancel the sale of a plutonium reprocessing plant to Pakistan and in 1985 it blocked the transfer of reprocessing technology from Argentina to Libya. When U.S. allies Taiwan and South Korean began reprocessing programs in the late 1970s, the United States threatened to withdraw America’s security guarantee if the programs continued and the countries relented. As one Taiwanese scientist said, “After the Americans got through with us, we wouldn’t have been able to teach physics here on Taiwan.” In a 2008 nuclear deal with the United Arab Emirates, Washington developed a new “gold standard” for peaceful nuclear cooperation, requiring that in exchange for American nuclear assistance Abu Dhabi agree to forswear any future enrichment and reprocessing regardless of the source of the material.Washington has bargained with rogue states over disputed nuclear programs in the past, but its terms were always clear and uncompromising: Sensitive nuclear technologies would not be allowed. The 1994 Agreed Framework with North Korea permitted light-water nuclear reactors, but not plutonium reprocessing. When it became clear that Pyongyang had been cheating on the deal from day one by secretly enriching uranium, Washington sought to shut that program down, demanding nothing less than “complete, verifiable, and irreversible disarmament.”In an agreement with Libya in 2003, a textbook example of successful nuclear diplomacy, Moammar Qaddafi agreed to give up everything. U.S. military aircraft transferred over 55,000 pounds of nuclear equipment out of the country, including its stockpile of centrifuges and centrifuge parts, within weeks of concluding the deal.Which brings us to Iran. Throughout the 1990s, suspicious procurement patterns led the United States to believe that Iran was building a secret enrichment program. In 1995, Moscow agreed to provide Iran with a uranium enrichment plant, but Washington intervened and convinced Russia to cancel the deal. The United States could live with Iranian nuclear reactors at Bushehr, but uranium enrichment was out of the question. Then, in 2002, a dissident group in Iran announced that Tehran was building a secret enrichment facility at Natanaz. The United States immediately demanded that Iran halt its enrichment program. The position was not harsh or unexpected: It was simply a continuation of decades of U.S. nonproliferation policy.The United States, under Presidents George W. Bush and Obama, worked to bring the rest of the world on board. In six separate U.N. Security Resolutions, the international community demanded that Iran “suspend all enrichment-related and reprocessing activities.”Then, suddenly, in what can only be described as a desperate attempt to get a deal with Iran regardless of the terms, the Obama Administration abandoned this 70-year-old bipartisan mainstay of U.S. nonproliferation policy—a policy that has stopped many countries from getting the bomb and thereby reduced the global threat of nuclear war. In the interim deal with Iran in November 2013, Washington and the rest of the P5+1 recognized a de facto right to enrichment in Iran. Over the past 18 months, the United States has engaged in the unprecedented act of haggling over the size and scope, not the existence, of an illegal enrichment program in a rogue state.Some of my colleagues argue that a deal that places limits on Iran’s enrichment program would be a logical extension of U.S. nonproliferation policy. They claim that in the past, when the United States has failed in its initial goal of preventing the spread of sensitive nuclear technologies, it has negotiated to place pragmatic limits on other aspects of nuclear programs. In confidential understandings with South Africa, Pakistan, and Israel, America contented itself with limits on nuclear testing, weaponization, and public declarations of nuclear weapons capabilities, respectively. Therefore, they argue, Iran should be no different.There are several problems with this line of argumentation but foremost among them is that all the examples these critics cite are of countries that were already de facto nuclear powers and that eventually went on to build the bomb. If Washington’s goal is to simply manage Iran’s entry into the nuclear club, then the proposed nuclear deal can be rationalized. But that is not the case that the Obama Administration is making to Congress and the public, where there is a bipartisan consensus in favor of a policy of prevention.A deal that allows Iran to keep a uranium enrichment program will not prevent Iran from acquiring nuclear weapons. Instead, it will make an Iranian bomb more likely. It also increases the risk of a nuclear arms race in the region. Then there is the matter of setting a dangerous precedent: It will be impossible for Washington to argue that it trusts Iran with sensitive nuclear facilities but not its friends and allies. To make matters even worse, in the wake of a deal, all of this will happen with the international community’s stamp of approval. Seventy years of successful U.S.-led nonproliferation policy will have been trashed.In sum, if to this point you have been confused about the arcane technical details in the Iran nuclear negotiations, save yourself some trouble. Unless the negotiators return to insisting on zero enrichment, their efforts deserve zero support.***Like this article? Sign up for our Daily Digest to get Tablet Magazine’s new content in your inbox each morning.