Daniel Larison makes a very strong point:  the world does not like the US because of its policies, and the symbolism of an Obama presidency will do little to heal the rifts and unavoidable tensions with the rest of the world:

As I have said before there is scarcely a more disrespectful, condescending attitude towards the rest of the world than the assumption that they can be bought off or won over with something as superficial as a U.S. President with a mixed racial background.  If the Obama fans actually believe their candidate has some legitimate policy changes to introduce, that might be a reason for other nations to respond favorably to him, but on the whole the changes on offer are, like so much else in this campaign, symbolic and aesthetic.  In the end, Obama fans project their own fantasies about “racial reconciliation” into the international sphere, implicitly likening the majority of the world to our minority populations, which is to belittle them a second time.  This relieves them of the obligation to critique seriously U.S. foreign policy, which is the source of some significant part of anti-U.S. animus, since they have already concluded that America’s reputation can be repaired in some measure simply through the election of one man. 

It sure doesn’t help that Obama knows he’s weak on foreign policy and sometimes plays the hawk, like an in-over-his-head manager playing the tyrant to rattle and silence his subordinates.  His appearance and background will do little to help him with counterparts ranging from China to Pakistan to Russia, and his lack of experience and interest in foreign affairs will provide an additional burden if he becomes the President.  George W. Bush is a good example of this problem in action: he could care less about world affairs before he became President, he’s been unduly influenced by idealistic-sounding idiots like Wolfowitz and Rumsfeld, mucking things up mightily because his ability to think critically about the sometimes conflicting advice he’s getting is severely compromised.