An obvious point, but Bush can seem disoriented or slow to act at first, as illustrated immediately following 9/11. Once he gets his bearings and decides to move, however, he moves. Putin may have underestimated him, believing that the polls or Iraq might constrain a US reaction, but he’s got to be worrying now. National pride and muscle-flexing notwithstanding, I doubt Putin intended or would be confident of tangling with the USAF and Navy. We didn’t have very convenient logistics in Afghanistan, either, and look what happened there.