manfromv:

Let us say, the President makes the policy to withdraw most army and left behind some to help out the Iraqis. Then this policy is carried out by the generals to decide the speed and how many to be left behind in consultation with the Iraqi generals considering all aspects of the situation.

Note, policy defines the what, and implementation defines the how. There is no conflict at all between our views.

I would submit that such an implementation is pretty much unworkable, as the timetable and number of troops is part of the policy decision. When the president says, "I want to withdraw troops," obivously it matters, policy-wise, whether that withdrawal takes place now or 100 years from now. When the president says "I want to withdraw most troops," he has to decide what size footprint to leave behind, and that decision is more than purely a military decision. The generals can all consult and tell him the pros and cons -- as they see it from a military perspective -- of different withdrawal strategies, but obviously the president isn't going to leave it up to his generals (let alone foreign generals) to decide everything.