Recently, according to the New York Times, GEN Cody, Vice Chief of Staff of the Army, was asked about problems in Iraq. One of his responses was that the politicians who cut the Army in the 90's are to blame. In 1991, for Desert Storm, there were 18 active Army divisions and 10 National Guard Divisions. Today there are 10 and 4 respectively. Granted a 2007 brigade is much more capable than a 1991 brigade, but it would be nice to have 30 more. This would solve two of the problems with the current war. It would allow units to rotate less often, and it would provide more troops on the ground. I think GEN Petraues has proved with the surge that the key is to have more troops available in Iraq.
Even if the Soldier of 1991 was less capable individually then today, and he certainly is better equipped in all areas except combat rifle, 80% more would be a good thing.
Of course, without a draft or the enlistment of foreign mercenaries there is no means available to quickly grow the Army 80%.