THE IDEOLOGY'S THE THING. I'm not so high on this "Bush wants to bomb Iran to secure his legacy" concept. As we enter into the twighlight years of Bushism, it's important to avoid ascribing problematic elements of the past five years of American governance to Bush's personal idiosyncrasies when, in fact, the real source of the problems are deeper and wider ideological movements. Mark Steyn didn't publish this crazy article on Iran because Bush is looking for a legacy. Nor did Mark Helprin write this crazy op-ed on Iran because Bush is looking for a legacy. Nor did Fred Hiatt publish Helprin's op-ed because he's looking for a legacy. Nor are Frank Gaffney and Jon Kyl pushing crazy Iran policy ideas because Bush is looking for a legacy.
Rather, there's a widespread view on the American right that it's always a mistake to reach diplomatic agreements with "evil" regimes. There's also a widespread view on the American right that, contra the examples of Joseph Stalin and Mao Zedong, nuclear deterrence won't work against "crazy" leaders. At the intersection of those two opinions is the conclusion that we ought to be very, very, very, very willing to use unilateral preventative military force against countries that have nuclear weapons programs or that we merely vaguely suspect of having nuclear weapons programs. Both of those ideas are foolish and dangerously wrong, but they're also widespread -- not private oddball notions of Bush's. If liberals want to push this country's foreign policy in a better direction over the next five-to-ten years, we need to attack the whole network of ideas (including a non-trivial number of ideas whose origins are inside the Democratic coalition) that gave us the Iraq War and that threaten to give us the Iran War.
Bush's poor leadership skills have made and continue to make things worse than they might otherwise be, but the basic problems here are much bigger than the man himself.