President Obama approved a new round of sanctions on Iranian oil Friday in what must have been a complicated judgement call that weighed diplomatic strategy against Iran and gas price-related election year politics. 

The Associated Press reports that Obama will approve a new set of rules punishing foreign banks that purchase Iran's oil, with exceptions for friendly countries that take steps to reduce their Iranian oil imports. He's walking a very thin diplomatic line as he tries to pressure Iran to abandon its nuclear weapons ambitions even as he tries to avoid military conflict, and Friday's sanctions are a part of that strategy. Complicating matters is the 2012 election, in which gas prices have become a political wedge. The AP says Obama ruled that there's enough oil available on the international market that further sanctions won't drive up the already high gas prices.

What will be really interesting to watch is how Republican candidates react to the news. We've already wondered whether Obama and the Republican candidates actually have the same policy on Iran even as the canddiates try to portray their ideas as different. But given Mitt Romney has often said his solution would be to strengthen existing sanctions, Friday's news ought to make the policy differences between him and the President even narrower. Somehow, we don't expect that to come through when both candidates are out campaigning.