So now more weapons will flow in and out of the city...
Yes, but sometimes the correct move strategically is a problem for the local operational or tactical situation. This is one of those times.
Convincing the Iraqis that we really are just there to help now, that it's their county, is part of the way to victory. This may cost lives over the next few weeks, but it and a few other moves of the same political import should save more lives in the long run.