Nuclear diplomacy, not force, offers the safest, surest route to rein in Iran

With the latest round of nuclear talks between Iran and the P5+1 world powers only in its first day, a global agreement to ration second world war references is sorely needed. Commentators have invoked Churchill, Munich and Hitler – with some North Korea references thrown in – toargue that Iran's nuclear program, and the Tehran regime's ideology, represent such a threat that nothing but a military response will do.

It's time for a dose of reality, however. One needn't see Iran's newly-elected President Rouhani as benign, or even as a profound break from the clerical regime's policies, in order to survey the facts and conclude – as a broad, bipartisan consensus of military and security leaders has done – that the deal on the table is the best way forward.

As Ken Pollack notes in his recent survey of US-Iran policy options, Unthinkable, we aren't really sure what the regime's goals are – and it may not be either. However, if we begin by imagining that some of the more pessimistic assumptions are correct – that Iran will seek regional dominance and nuclear weapons capability no matter what, and attempt to cheat on any agreement that is reached – the arguments for a negotiated settlement, even a less-than-perfect one, don't get weaker. They may actually get stronger.

If Iran's leaders are truly bent on regional or even world domination, they're doing a terrible job. In just the last five years, Iran's regional image has plunged as it repressed its own "green revolution", while other Middle Eastern societies, where citizens made similar calls for genuine, representative democracy and an end to corruption, had greater success.

Hostility toward the Shia sect of Islam, of which Tehran rules the world's largest concentration, has grown into open talk of regional warfare, with the battlefield spreading from Syria. The pressures of the Arab awakenings and Sunni-Shia tensions lost Iran its Palestinian ally, Hamas, which had been a key tool to Iran's ability to harass and threaten Israel; Tehran no longer has any influence on Hamas's actions.

Iran now faces global opprobrium for the actions of its Syrian ally. Its military and cyber aid have failed to be decisive for Bashar al-Assad, but they do serve as another drain on Iran's sanctions-stressed treasury and as a source of popular resentment abroad. Now, instead of overseeing a solid Shia crescent through Iraq, Syria and Lebanon – poised to threaten Turkey, Israel and the Gulf – Tehran presides over three weak or tottering regimes, plus its ally Hezbollah, which it pressured to turn away from its anti-Israel focus to make an all-or-nothing bet on propping up Assad in Syria.