I too read Andrew Sullivan's entirely unsurprising endorsement of Kerry, and while he advances an argument I'm sympathetic to--that while the decision to go to Iraq was right, the administration screwed up in major ways once it got there--he also advances some of the most oft-seen, and to my mind unconvincing, reasons to trust Kerry with national security:
Does Kerry believe in this war? Skeptics say he doesn't. They don't believe he has understood the significance of September 11. They rightly point to the antiwar and anti-Western attitudes of some in his base--the Michael Moores and Noam Chomskys who will celebrate a Kerry victory. I understand their worries. But they should listen to what Kerry has said. The convention was a remarkable event in that it pivoted the Democratic Party toward an uncomplicated embrace of the war on terror. Kerry has said again and again that he will not hesitate to defend this country and go on the offensive against Al Qaeda. I see no reason whatsoever why he shouldn't. What is there to gain from failure in this task? He knows that if he lets his guard down and if terrorists strike or succeed anywhere, he runs the risk of discrediting the Democrats as a party of national security for a generation. He has said quite clearly that he will not "cut and run" in Iraq. And the truth is: He cannot. There is no alternative to seeing the war through in Iraq. And Kerry's new mandate and fresh administration will increase the options available to us for winning. He has every incentive to be tough enough but far more leeway to be flexible than the incumbent.
Besides, the Democratic Party needs to be forced to take responsibility for the security of the country that is as much theirs as anyone's. The greatest weakness of the war effort so far has been the way it has become a partisan affair. This is the fault of both sides: the Rove-like opportunists on the right and the Moore-like haters on the left. But in wartime, a president bears the greater responsibility for keeping the country united. And this president has fundamentally failed in this respect. I want this war to be as bipartisan as the cold war, to bring both parties to the supreme task in front of us, to offer differing tactics and arguments and personnel in pursuit of the same cause. This is not, should not be, and one day cannot be, Bush's war. And the more it is, the more America loses, and our enemies gain.
The idea that we should trust Kerry, even if we think his previous foriegn policy instincts have all been bad, because he has nothing to gain from failing to pursue Al Qaeda, makes little sense. Surely George Bush had nothing to gain from failing to suppress the insurgency in Iraq, and yet his administration still hasn't done so. This argument seems to fall into the partisan assumption that if Kerry fails it will be out of malice. But most people who think that Kerry isn't the right man for the job think he will fail not because he wants to, but because he's fundamentally wrong in some way in his national security strategy.
Similarly, it doesn't strike me as very logical to imply that Democrats have abandoned national security issues, and then suggest electing them anyway as a way to force them to "take responsibility" for national security, any more than I would employ a drug addict in a pharmacy on the theory that this would force him to "take responsibility" for enforcing our nation's drug laws.
One may believe, as many do, that Kerry will be better on national security for other reasons. Andrew Sullivan offers several of them in his peice. But neither of these two strikes me as very compelling.