I have LONG contended that the Army needs 6 to 8 more combat brigades and the Marines 3 or 4 ... just to cope with the current rotation schedule in Iraq.
If we are going to take on Iran as well, we had better double the entire military.
In war, there are three thing that you are always short of, men, ammo and enemy dead.
I think that's in the works. May be tough to get done in time of war without a draft.