10,000 Won't Do It: The Mathematics of an American Deployment to Fight ISIL

I have mentioned this probably half a dozen times. Getting a bunh of guys into the middle of the Caliphate is not a piece of cake.

In the case of a campaign against ISIL, the length of the lines of communication in this theater of war, from seaports and airports to key ISIL-held cities, is daunting. From our bases in Kuwait, it is roughly 1,000 kilometers to Mosul. To Raqqa it is another 400 kilometers. If we were to attack ISIL through the Syrian port of Latakia, the distance to Raqqa is 300 kilometers. We can assume these lines of communication will be contested. It may well only require two U.S. brigade combat teams, along with French, Russian, Turkish, Kurdish, Jordanian, and Iraqi forces to defeat ISIL in combat. Nonetheless, it will take a lot more than 10,000 soldiers to deliver two brigade combat teams to Mosul and Raqqa in the form required to engage in battle with an enemy who clearly knows how to fight.

We professionals know this because we know the mathematics of war. We cannot forage our way to Mosul and Raqqa. Fighting and defeating ISIL in Mosul and Raqqa is also not the end of the required action. As Boot pointed out in his Policy Innovation Memorandum, a strategy to defeat ISIL requires the United States to “[p]repare now for nation building.”

The mathematics of war also considers the “troop-to-task” ratio. In order to establish conditions of security such that the range of U.N. agencies, private and non-governmental organizations, and even Iraqi and Syrian national agencies will restore life-sustaining functions to towns and cities, a strategy has to include forces for, as Boot pointed out, “nation building” or “re-building.”

This is not blind obedience to the Powell doctrine of overwhelming force. Our military advice needs to take into account what it takes to go to the war, fight and win the war, sustain the war, and settle the war enough to handover to a transition force. If we are just conducting a punitive expedition, this is another case entirely. We can then just execute the punitive action, withdraw the force and return home.

Highlighting this need for clearly stated military advice is this example drawn from former Secretary of Defense Robert Gates’ memoir Duty. Military advice must take into account the problems which stem from a different baseline knowledge of military matters between military professionals and policymakers. Gates cites an incident that occurred during the summer of 2009 when he debated President Obama on troop numbers for the Afghan surge. This disagreement was driven in part by a lack of understanding of what the range of numbers included. When Secretary Gates explained that the military had assumed that the 5,000 “enablers” would be in addition to combat troops and were not part of the additional 21,000 troops that the military had requested, President Obama angrily asserted that this was “mission creep” and that the public and Congress would not differentiate among types of troops and only look at final numbers deployed. In this instance professional officers were incorrect in assuming, on behalf of some of their civilian leaders, a depth of understanding of the mathematics of war. "