US has shot itself in the foot, internationally-speaking

Peter Galbraith's article How to Get Out of Iraq points out how a three-state federal system in Iraq is likely the only workable form of government for this country (as I talked about a couple of weeks ago, too.) Galbraith goes on to talk about the importance of internationalizing the effort.
Only with his conclusion do I have a problem. He writes thatIraq demonstrates all too clearly the folly of the preventive war doctrine and of unilateralism. Of course the United States must reserve the right to act alone when the country is under attack or in imminent danger of attack. But these are also precisely the circumstances when the United States does not need to act alone and he goes on to talk about the continuing worldwide support for the war in Afganistan.
But Afganistan was before Iraq, and before a host of other American foreign-policy blunders -- ham-handed favouritsm for Sharon, self-serving tolerance for Pakistan's nuclear proliferation, clumsy feints with North Korea, confusion over Taiwan/China issues, and stunningly poor WMD intellegence. No other nation now would actually believe any claim by the Bush Administration about an imminent threat, nor would we trust the US to lead any international effort again. So the US is truely on its own now.