Tuesday was the worst day of the George W. Bush administration. The deal U.S. President Barack Obama has struck with Iran to curb its nuclear weapons program amounts to a pragmatic recognition that Iran has joined the U.S. as a crucial regional player not just in the Persian Gulf but also in the whole Middle East. Iran's rise wouldn't have been possible — and the deal wouldn't have been necessary — had the U.S. not unleashed Iran from the regional power that did the most to contain it: Saddam Hussein's Iraq.
Start with the deal announced Tuesday, which reflects what the history books will identify as Obama's distinctive foreign policy approach. He inherited a world in which the unquestioned U.S. hegemony that followed the end of the Cold War was beginning to erode. Faced with rising powers such as China in the Pacific, Russia in eastern Europe, and Iran in the Middle East, Obama has responded by rejecting overt confrontation or aggressive containment that might lead to direct conflict. Instead, he's favored calm, pragmatic acceptance of the rise of the challenging power.
To hawks and proponents of containment, this amounts to a form of defeatism. But to a certain strand of foreign policy realists, it's just good common sense. If you can't — or won't — stop a power from rising, you might as well engage it and try to reduce the risks of violence.