There are certainly considerations that we must make with regard to the level of the forces,

Certainly our goal is to leave Iraq, but we can't leave Iraq with our forces until we know that the Iraqi security forces are capable and efficient enough to defend the sovereignty of the nation.

The NATO forces are coming,

It makes sense that as NATO forces go in, and they're more in numbers, that we could drop some of the U.S. requirements somewhat,

But clearly the fact that we've gone from zero Iraqi security forces on duty in May to up to 200,000 today is an enormous accomplishment, but it's not enough.

But the key shift in focus will be from counter-insurgency operations to more and more cooperation with Iraqi security forces and to building Iraqi security capacity.