An e-mail:

Dear Mr. Lowry,
Before you go and say anything about this subject, it would be good if you could study the breakdown of troops by type in Iraq. After all, we have somewhere between 130-150 thousand men there, and the British conquered and held India with little more than a third of that number. So what gives?
The answer lies in the types of troops. Counter-insurgency is a type of warfare best fought by very high calibre light infantry, backed up by substantial numbers of special forces. All other types of troops play very minor supporting roles. So how many light infantry are there, among our nominal 130-150 thousand? Probably not much more than 25,000 in all. Remember, even today most of our troops there are from heavy armor/mechanized divisions, which have 18,000 men on the TO&E, but only about 2500 dismountable infantryman. All the rest of the men are tankers, artillerymen, air defenders, maintenance technicians, drivers and the like. Stryker brigades of 3500 men have almost as many infantry. However, in neither case can these troops be called “light infantry”. They are, rather trained to move to the point of contact in their vehicles, dismount and assault the objective directly. They rely on heavy weapons, whether vehicular or indirect fire. They are not trained for the kind of stalk-and-ambush tactics of true light infantry. Even our “elite” light infantry units–the 82nd airborne, the 101st Air Assault, the 10th Mountain and the 75th Ranger Battalion rely on conventional fire and movement tactics. Only in the elite of SOCOM can you find the right sill set, and you cannot expand special operations quickly without diluting quality (one lesson of Vietnam we did not forget–yet).
So, if you are going to deploy more troops to Iraq, remember that the net increment in effective combat power is very small relative to the total number of troops deployed. Worse still, all of these heavy forces have a large “logistic footprint”. An armored/mechanized division requires about 2000 tons of supplies each day (a brigade would require about a quarter of that), all of which has to be brought overland from ports at the mouth of the Tigris and Euphrates or from inside Kuwait. Each truck convoy needs its own escort force. Each new unit needs cantons with perimeters and security details. At the end of the day, any new unit deployed to Iraq expends much of its manpower taking in its own laundry, leaving very little surplus for fighting terrorists and maintaining order.
The problem won’t go away until the entire U.S. Army is transformed, and that is not going to happen quickly, given institutional opposition to Secretary Rumsfeld’s various initiatives–many of which, incidentally, aren’t entirely a propos of this kind of war.
The only answer, then, is to rely more heavily on the Iraqis for better or worse…