Iran is almost certainly trying to build a nuclear bomb right now. For the past four years, President Obama has been trying to get Iran to back down with a combination of rewards for nonproliferation and sanctions in the meantime. Why has Iran ignored us thus far?

A lot of people believe that you simply cannot appease rising states in this manner–they need weapons to secure concessions, so bargaining is fruitless. A few years ago, I was one such person. But in my effort to verify what I thought, I discovered I was wrong, and turned my results into an interesting paper. Settlements almost always leave both sides better off, even if the rising state can freely take the concessions and proliferate anyway.

So, again, why is Iran trying to proliferate?

I have a working paper that I think provides a reasonable explanation. (It is still preliminary, so I am not posting it here. Please email me and I will gladly send you a copy, though.) Conventional wisdom portrays Iran as the villain and us as the good guys. But if you think about the situation from their perspective, Iran’s motivation will be obvious.

The United States has always had a bad relationship with Iran since the revolution. There was a glimmer of hope on September 11, 2001 when Iran (quietly) assisted us with the invasion of Afghanistan. But that cooperation tanked when Bush declared Iran part of the “axis of evil” a few months later. This infuriated Iran, and things went cold for a couple of years.

Nevertheless, Iran again extended an olive branch in May 2003 in a remarkable effort that has amazingly escaped our collective memory. Iran put everything on the table–full diplomatic relations, dropping the nuclear program, recognition of Israel, ending support of Hezbollah, help with al-Qaeda–and asked for shockingly little in return. It is the type of deal we would jump at today, so much so that it is difficult to believe it was within our grasp just nine years ago.

How did Bush respond? He didn’t.

Yes, you read that correctly. The Bush administration completely ignored the offer.

So consider how Iran views Obama’s overtures. Iran knows the United States is weak right now–yet another war in the region would be difficult at the moment. So Iran has two choices. Option one is to proliferate now while it is still an option and force the United States to play ball in the future. Option 2 is accept Obama’s concessions now and hope the United States will continue them into the future without the threat of nukes in the background. Given the experience from 2003, which would you choose?

The unfortunate part is how inefficient the result is. Both sides would be better off if the United States could credibly commit to continued concessions into the future. But because the U.S. cannot, we are stuck with Iran attempting to go nuclear.

Of course, this does not mean proliferation will certainly be the ultimate outcome. Trade sanctions could lead to some domestic shock which changes Iranian priorities entirely. The proliferation process itself is uncertain as well; it is possible that Iran will find that proliferation will take too long and ultimately give up. But until we reach that point, don’t expect U.S.-Iranian relations to suddenly thaw.