Pursuing a changed relationship with the United States, Mikhail Gorbachev eventually made the major concession of allowing inspectors into Soviet nuclear facilities. Iran, Michael Mandelbaum writes, is quite a different case:

As the result of Gorbachev’s policies, the Soviet-American rivalry was ebbing. Because the Soviet government sought better relations with the United States, it cooperated with the inspectors. The Iranian government cannot be counted on to adopt a similar attitude: while it is seeking relief from internationally-imposed economic sanctions, unlike Gorbachev it does not want to improve its relationship to the United States. Unlike Gorbachev, it shows no sign of reconsidering, let alone discontinuing, the policies that have put it at odds with America.

During the cold war, American arms-control policy was linked to Soviet foreign policy. When that policy waxed aggressive, it became politically impossible to gain the necessary political support in the United States for an arms-control accord. . . . The Obama approach to the Iranian nuclear program has had, if anything, the opposite effect. As the negotiations have proceeded, the Iranian regime has expanded rather than pulled back from the initiatives that threaten the security of countries aligned with the United States. . . . Iran also continues to proclaim its intention to destroy Israel, a project that an Iranian nuclear arsenal would make horrifically feasible. By the terms of the agreement that have been revealed thus far, Iran will get relief from economic sanctions without having to modify any of these policies. . . .

Even if the talks do produce an accord that all parties sign, with the resulting removal of economic sanctions and with the theoretical option to re-impose them being almost certainly unworkable in practice, the mullahs will have no incentive other than the threat of bombardment to exercise nuclear restraint. . . . Asserting [as many do] that the United States should not stop the Iranian program by force because that will only buy time is like saying that medical care is pointless because everyone ultimately dies.