You can read about it here in Foreign Affairs. As Ilan Goldberg says it tends to prompt a sensation of whiplash, “One second he is totally reasonable. The next second I think he’s completely clueless.”
The sad truth is that this is better than most of what you get on this topic from the other Republicans. Rudy Giuliani’s comparable essay, for example, was completely free of “totally reasonable” moments. That said, as soon as Mitt Romney attacked Huckabee for criticizing Bush’s “arrogant bunker mentality” Huckabee decided to back down. Nobody in the Republican field is ready to explicitly argue for a break with Bushism except Ron Paul.