The historical judgment on Iraq and Iran approaches

I was reading this Daniel Drezner post today, and I got thinking about how historians will look back on our approaches to the problems we faced in Iraq and Iran. In his piece, Drezner asserts that the way we have dealt with Iran so far is probably not discernibly different from how a President Kerry's administration would have done things. So if we say that approaches to Iraq and Iran represent the two major schools of thought out their right now on dealing with external threats, which will history look back on as being more correct and effective? It is difficult to say right now since we are still in the middle of our efforts with both countries, but I think if Iran develops and uses a nuclear weapon in the next 5-10 years, the way we handled Iraq is going to look like the better decision.