"Does the need to train troops for urban combat provide enough justification for the military to conduct realistic exercises in actual US cities?" is how I wish I had written that.
I hope my other comment sufficiently addressed that "urban combat" was not the task being trained in that exercise. There are places the military trains for "urban combat" ... Main St. USA is not it.
I'm...seriously baffled as to what confusion of ideas would lead you to say something like this. Do you not know what the word "training" means?