Are there enough troops? No, not if you want to have combat ready troops available for another emergency. Normally, the troops are on a training schedule, where they train for a year or more, and they stand ready (and well trained) for emergencies until the cycle begins again. This period of peak capability doesn't last long, as experienced troops get out of the service or are transferred to other jobs. By keeping so many troops overseas in peacekeeping operations, they lose their combat skills. This happens even though they are in combat, and that is because they are usually only engaged in a few specific types of operations. The purpose of combat training is to make the troops capable of a wide range of operations. The loss of capability will result in more troops being killed or injured in future combat operations. Another problem, because it is a volunteer force, is fewer troops staying in the service, or joining in the first place. Overall, however, the loss in combat capability is not catastrophic, as the Iraq operation won't last forever. But many military leaders are calling for increasing the strength of the Army for as long as so many troops are needed overseas. But no one knows how long the Iraqi occupation will last, and it's will cost tens of billions to raise, say, two additional divisions. But Congress will probably not be willing to provide all the money needed, forcing the army to cut back on training and development of new weapons and equipment. The generals don't want to do that either, because they know it is possible. During the Balkans peacekeeping of the 1990s, Congress regularly forced the Army to pay for the peacekeeping operations by cutting back on other activities (training, troops housing and new equipment.)
The U.S. Army is facing a troop shortage. Currently, the U.S. Army has a total of 368,900 (54 percent) of 684,000 troops on active duty (485,000 regulars and 199,000 reservists called up to active duty) serving overseas. Most of them are in Iraq, Germany, South Korea, the Balkans and Okinawa. But smaller detachments are in over a hundred other countries. Normally, troops are assigned to these overseas areas for periods ranging from six months to three years, depending on how dangerous or uncomfortable the place is. Western Europe is a three years tour, and there are plenty of volunteers. The Balkans is a six months tour, and there are far fewer volunteers. South Korea is thirteen months and there are some volunteers. Iraq is a place where the fighting isn't over yet, but the decision has been made to send troops over there for one year (for regulars) and six month (for reservists) tours. Units already there will sent home on a "first in/first out" basis. Units will not be replaced man for man. For example, the first unit to go home, the 3rd Infantry Division, will be replaced, in September, by two brigades of the 82nd Airborne Division. The U.S. 1st Marine Division will be replace at the same time by an international (mostly Polish) division. In February and March, the U.S. 101st Airborne Division will be replaced by more international troops (which have not been recruited yet, so that may change.) The U.S. 4th Infantry division will go home next April, replaced by the 1st Infantry division (including a National Guard brigade). The 1st Armored division will be relieved next May by the 1st Cavalry Division (including a National Guard brigade). The 3rd Armored Cavalry Regiment will be replaced by one of the Army's new Stryker (armored car) regiments this October. But the 3rd Cav won't go home until next Spring. The brigade from the 82nd Airborne division will go home in January, and will not be replaced. Same for the 173rd Airborne Brigade, which will depart for it's Italian base in April.