By Marina Malenic

The Defense Department is weighing the pros and cons of increasing the number of light, mobile Army Stryker brigades at the expense of further cuts to the service’s heavy, tank-based brigades, the Army’s top uniformed officer said yesterday.

“As we’re looking to this Quadrennial Defense Review, we’re looking hard at whether we need to increase the number of Stryker Brigade Combat Teams,” Gen. George Casey, the Army’s chief of staff, told a panel of the House Appropriations Committee. “My inclination is that we do have a very capable system here that fills a middle weight on the spectrum.”

Lawmakers last week agreed to include $338.4 million for 225 of General Dynamics‘ [GD] Stryker medical-evaluation vehicles and 35 Stryker engineering- squad vehicles in this year’s supplemental war-funding bill. The troop carriers have been widely used in Iraq and, according to Casey, have begun arriving in Afghanistan for the first time.

Over the past two decades, the Army has converted 200 tank battalions and air defense and artillery batteries–units designed specifically for conventional warfare–into lighter forces, according to Casey. As the Army looks to the future and prepares for a mix of conventional and irregular conflict–what the Pentagon has begun calling “hybrid warfare”–it is looking to further divest itself of Cold War relics that leaders say are no longer relevant in that type of combat environment.

“One thing about the future is that you never get it quite right,” Casey told lawmakers. “So what we need to do is build a versatile mix of forces–heavy forces, Strykers and infantry forces…mounted on” heavily armored vehicles such as Mine Resistant Ambush Protected (MRAP) trucks.

To that end, the service is now looking to replace its aging M2/M3 Bradley Fighting Vehicles with a new combat vehicle expected to be designed by the fall and fielded in as few as five to seven years. BAE Systems builds the Bradley.

“The Bradley is a Cold War system,” Casey told reporters following the hearing. “It’s at the end of it’s useful life.”

But even though the Army may want fewer heavy brigades over all, the weight of their combat vehicles is likely to remain at or around the Bradley’s 25 tons for the foreseeable future, according to Casey. On a recent visit to Aberdeen Proving Ground, Md., where the Pentagon conducts automotive and direct fire testing, the general said he asked Army experts how much armor is necessary to protect soldiers from roadside improvised explosive devices (IEDs).

“I asked them when I was up at Aberdeen…what’s the weight that will sustain the underbelly?” he said. “And they said it’s better than 25 tons.”

Defense Secretary Robert Gates earlier this year canceled a new combat vehicle development effort that was part of the Army’s multibillion-dollar Future Combat Systems modernization program. Gates found fault with the prototypes’ lack of armor and other defenses against IEDs.

Army leaders have clearly taken that criticism to heart.

One of the lessons we have learned is, you’ve got to be a certain height off the ground and you have to be heavy enough to take a blast–it’s just physics,” said Casey. “So anything we come out with will meet those criteria because we’re going to be operating in an IED environment for as long as I can foresee.”