Part 17 of Why its so damn difficult to have any sort of meaningful debate about the future of US policy in Iraq, and part 34 of why the Bush Administration has a serious credibility problem when it comes to anything Iraq related.First, Bush says we can't leave:President Bush warned Thursday that pulling out of Iraq too soon would trigger a bloodbath akin to that of the Cambodian killing fields of the 1970s...."I want to remind you that after...