Mr. Buckley is, of course, correct.
I knew Bush wasn't a true conservative in 2000, but I nevertheless supported him, because the alternative was too horrible to consider. He was passably conservative on enough issues, in my opinion, and when he selected Cheney as his running mate, I figured he was all right.
As to the war, I was ambivalent about it up to the moment we invaded. Once that was done, though, we were committed, and have to remain so until the job is done, in my opinion. Bickering about it accomplishes little, and detracts from the ability of the military to succeed. I wonder if Buckley is critical of the idea of the war, or the way it has been fought. There are, I think, some legitimate criticisms there.
Regardless, overall, Bush has been at the very least, a caretaker for the conservative movement, and has been good in a few spots (sanctity of human life, epecially), decent enough in several others (tax policy and economic growth), despite his shortcomings (spending, size of government).
Bush deserves credit where credit is due, but let's not go overboard and make him out to be some kind of conservative icon, which he is not, and has never been.
I forgot to mention that Bush has also been very good on judicial appointments, save the Harriet Myers fiasco.