One thing the Marine Corps taught me is that a 70% solution acted on immediately and violently is better than a perfect solution acted on later. My experience has proven this true time and again. The sad fact is however, that a 70% solution is a 30% mistake. And those mistakes can be hard to take. In WWII for example, 700 soldiers drowned in a training accident in preparation for D-Day (that is about how many combat deaths we've experienced so far in Iraq).
Bush is making mistakes, absolutely he is. And I think that he is making a greater one by not owning up to them. When it comes down to the final tally, I think that his actions are creating more good than harm in the long run. From what I have seen of Kerry's foreign policy, it is more of the same old "anything but taking a risk of messing up" that characterized much of the past thirty years.