I would not say to the MAX, sure it is a change of policy but not sure it would classify as flip flopping. Foreign policy is not something etched in stone. You have to be flexible and move with what is happening on a day to day basis.
Many times hard stands like the administration had before are just a bluff to see if they can get what they want and if that does not work then you have to change your approach to the problem.
Also problems change and so does the Intel that we do not see. Maybe the administration knows something that we do not know, and decided it is in the U.S. best interest to be there. Maybe they want to be there to keep things in check and not allow Iran and Syria to bully Iraq into something or make a deal under the table.
Who knows why the policy changes. But foreign policy changes are a lot different than supporting something one day when it was in their best interest politically and then changing when they decide it would better serve them to change their views. Much like the Dem's did on the Iraq war.
I doubt Bush has much to gain or loose politically by changing his policy of talking to these countries. So I would not call that flip flopping, I would call that adapting to the ever changing situation in the Middle East.