‘Trust, but verify,” or its Russian equivalent, “doveryai, no proveryai,” was a saying US president Ronald Reagan favored during arms control negotiations with the USSR’s Mikhail Gorbachev.Eventually, negotiations bore fruit and both superpowers destroyed thousands of nuclear and conventional ground-launched ballistic and cruise missiles of intermediate ranges.The US and other nations should adopt the Persian version of this respectful but wary stance as Iran shows signs of willingness to enter into negotiations over its nuclear weapons program.On one hand, the Obama administration, the EU and other nations must accept at face value Iranian President Hassan Rouhani’s apparent overtures. Rebuffing what might be a sincere attempt at reconciliation might mean missing an opportunity to halt the Islamic Republic’s march toward nuclear weapon capability via peaceful diplomacy.At the same time, the White House must be wary of being duped into loosening the economic sanctions that are destabilizing the Iranian economy and generating political unrest, without first receiving verifiable evidence that the Iranians are closing down their nuclear weapon program.Unfortunately, there seem to be quite a few reasons to be wary of Rouhani’s intentions and very few to believe that the mullahs are truly ready to forgo their aspirations for a nuclear bomb.First of all, Iran’s nuclear weapons program is central to the regime’s deep convictions regarding its vulnerable position as a lone Shi’ite state in the Sunni-dominated Middle East. During the 1980-1988 Iran-Iraq War, when the Islamic Republic was losing tens of thousands of young men every month against the US-backed Iraqis, Iran’s leaders saw nuclear weapons as the ultimate trump card. The same argument rings true today as the Iran-backed Alawite President Basher Assad and other non-Sunni minorities in Syria are fighting for their lives against a coalition financed by Westernaligned Gulf states.Second, Rouhani’s triumph in the recent presidential election should not be misconstrued as ushering in an era of moderation and rationality in Iranian politics. It should, instead, be seen as a change of tactics. Rouhani may be attempting a divide and conquer strategy in which the Europeans, who are likely to be more susceptible to Rouhani’s charm offensive, are pitted against the Americans. And Israel, under Prime Minister Binyamin Netanyahu’s lead, might clash with the White House on the issue. At the very least, Rouhani might be acting on the reasonable belief that Mahmoud Ahmadinejad’s crude confrontational approach only hurt Iran’s nuclear program and that subterfuge and a false aura of moderation will more effectively further Iran’s goals.Third, Iran has reason to believe that the US and other Western powers are not serious about backing up sanctions with military action. This is not 2003, the year that Iran actually did freeze its nuclear weapons program out of fear that US president George W. Bush, who was massing men and weapons for an invasion of Iraq, would come after the Islamic Republic as well. As evidenced from the difficulties US President Barack Obama and British Prime Minister David Cameron encountered in mustering support for military intervention in Syria, the West is war-weary.Under the circumstances, before agreeing to lessen economic sanctions, the US and other nations must insist on verifiable, concrete steps that do not just delay Iran’s breakout date by a few months or a year but that effectively shut down the nuclear weapon program.“Trust, but verify” helped end the Cold War between the US and the USSR. We should not rule out the outside chance that the same combination of openness to diplomacy and dialogue and strict adherence to due diligence will pay off in negotiations with Tehran. But while Gorbachev was presiding over a USSR on the verge of collapse, the mullahs running the Islamic Republic, though smarting from economic sanctions, have too many reasons to press ahead with their drive for nuclear weapons capability.