The threat to the Armor force is in an area that seems to be constantly reshaping itself, the Army National Guard. At present, over 60 percent of the 19K-series (armor crewman) soldiers are in the National Guard. Given the success of units like the 3d Infantry Division during the Gulf War, you'd think the armor force would find itself revitalized. That's not happening on the state level, though, where the National Guard is managed. There are several reasons for this.
First, armor units are expensive. Moving a tank one mile costs over $150 in OPTEMPO (operational tempo, or training) money. For the same money, you can run several HMMWV's all weekend long. Ammunition is also expensive, and the limitations on when and where you can shoot it make live-fire training prohibitive. The training simulators, too, like UCOFT and AFIST, require specially-trained I/Os (instructor/operators) to lead the crews through training. Since there are very few states with more than one armor battalion (Ohio, Texas, California, Mississippi, New York), there are very few states where the 'armor lobby' is strong enough to get the money for these units at the state headquarters.
Second, the recruiting push among the National Guard has focused less on "serve your community and country" and more on "money for college" and "skills for civilian employment." While many civilian applications can be found for mechanics, radio repairmen, medics, and engineers, there are a finite number of civilian positions where the ability blow holes in things at 4 kilometer with an armor-piercing fin-stabilized discarding-sabot penetrating round. Signal units are much sexier in this regard.
Third, states are increasingly looking for units that can support non-military missions and emergencies. The National Guard has typically offered state governors an emergency force to assist during state disasters. These are usually natural disasters, such as hurricanes and wildfires, but can also include law enforcement. Engineer units are popular in this regard, because they bring bulldozers and backhoes with them. Even infantry units can provide a reasonable load of manpower to assist in clean-up efforts. Armor units are doubly-constrained in this area: they have few, if any, 'emergency assistance' assets, and relatively small amounts of manpower. A typical infantry company has 100-120 soldiers; a tank company has 60-80.
Fourth, armor units are suffering from horrible retention rates. Part of this has to do with the recruiting focus, but a greater concern is the number of deployments these soldiers have incurred, without their tanks. 1-108 AR from Georgia deployed to Bosnia several years ago, and their strength has declined over 20 percent since they've been back. 1-263 AR from South Carolina is currently on homeland defense duty as gate guards for 5 bases across two states, and their problems are compounded by the fact that they are coming back to reserve status in three different groups up to a year apart, making them ineffective as a tank unit until 2005 at the earliest. Similar problems are being reported in Louisiana, Alabama, Ohio, California, and Washington. While deployments have been a sore spot for many units nationwide, infantry, engineer, and other units are still given the opportunity to train in their specialties while "deployed." Armor units, because of the expense, have few of these opportunities.
All told, despite the success of the armor force in the second Gulf War, there are serious issues afoot in the part of the Army with the most tankers: the National Guard. The recruiters won't recruit for them, the states won't budget for them, the federal government calls them up to do other jobs, and they don't have the manpower to stand up for themselves. It would not be surprising to find armor battalions completely phased out of states where only a small armor community exists, even in enhanced brigades.
The armor force of the U.S. Army is undergoing some radical changes, and not where people expect, either. Much to-do has been made of the plan to convert several army brigades to the new "SBCT" (Stryker Brigade Combat Team) concept (using wheeled armored cars instead of tracked vehicles). Accusations have been leveled that the army is getting 'too light' in using armored cars in lieu of tanks. This is, however, off-base. Of the brigades converting to the SBCT standard, only one was a mechanized brigade. The others are all either light infantry (Alaska, Hawaii) or HMMWV-mounted (2d ACR at Fort Polk).