If diplomacy fails, another Obama advisor wrote in the same report, the alternative “is a strategy of containment and punishment.” That was the conclusion of Ashton B. Carter, Obama’s reported choice as an undersecretary of Defense, who also warned: “The challenge of containing Iranian ambitions and hubris would be as large as containing its nuclear arsenal.Most (and maybe all) of Obama’s advisors see the costs of attacking Iran as outweighing the benefits. If Iran gets closer to acquiring nuclear weapons, they’ve warned, military action won’t look any more appetizing than it did under George W. Bush. But that doesn’t mean the United States would do nothing. Instead, Obama aides suggested in their writings, the U.S. should pursue a Persian Gulf version of the containment strategy used against the Soviet Union during the Cold War.