Doing the Troop Rotation Math

It is official, Sec. of Defense Gates has announced that all active duty US Army units will be seeing fifteen month combat tours with a twelve month reconstitution period at their permanent base. I just want to do a little bit of math on the current deployment patterns and probable future policy implications for the US Army.

Right now the US Army has forty three active duty ground combat brigades in combat, reforming from combat, or transforming from a triangular structure to an independent unit of action structure. These are the brigades that are affected. The US Army has several deployment slots that must be filled by this force structure. The first is a single brigade in South Korea, and the Army fills this requirement by the permanent stationing of an active duty brigade there. This force is not currently available for any rotation efforts.

Next the Army is responsible for two brigades in Afghanistan. The current policy is to rotate infantry units through. National Guard brigades have been used for this mission.

The largest deployment hole for the Army to fill is for the Iraq force. With President Bush reinforcing the failure of his Iraq policy to twenty brigades the Army has to fill most of these slots. The US Marines commit two reinforced brigade equivilants to Anbar Province, so the Army has to fill a requirement of eighteen brigades combat deployed.

Finally, from the forces left over the Army has to fill all other national security missions, train, rest, recuperate, and provide a strategic reserve.

So in a quick review the Army has 43 brigades, of which one iis permanently forward deployed in Korea. The other forty two brigades have to fill the needs for twenty combat deployed brigades, and all other needs.

The new rotation policy will theoretically allow the Army to do this without activating National Guard units as each active duty unit will be combat deployed for 55% of its operational cycle. This implies a theoretical [and massively impractical]23 combat deployable brigades in the active duty Army at any one time. 23 is greater than 20 so what is the problem?

The problem is simple, this assumes that the soldiers are mindless automations whose equipment is in good enough shape to allow for barely adequate training when they are deployed to the permanent garrison stations. That is not case on both counts.