The Bush administration and military leaders in Washington are always claiming that they will do anything to support American troops fighting in Iraq. That makes it all the more infuriating to learn that, for more than two years, the Pentagon largely ignored urgent requests from field commanders for better armor-protected vehicles that could have saved untold lives and limbs.

Improvised explosive devices, or I.E.D.'s, can blast through the flat underbelly of the military's standard Humvees, maiming and killing the soldiers within. These devices, a low-tech response to America's overwhelming military power, are now causing 70 percent to 80 percent of the American combat deaths in Iraq.

More than two years ago, according to newly disclosed documents, Marine commanders in Al Anbar Province, a center of the Sunni insurgency, submitted an urgent request for more than 1,100 Mine Resistant Ambush Protected Vehicles, or MRAPs, that have V-shaped bottoms able to deflect blasts from below. For reasons yet to be satisfactorily explained, military officials initially sat on the request and then ordered relatively few.

Some, second-guessing the judgment of the battlefield commanders, apparently felt that Humvees with upgraded armor could do the job. Others may have been reluctant to invest billions of dollars in vehicles that might have little use after Iraq. Turf battles were probably also a factor, as a large-scale purchase might threaten future weapons programs. But Iraq is the war that Americans are fighting and dying in today.

Only now are Pentagon leaders, prodded by Senator Joseph R. Biden Jr. and other critics on Capitol Hill, rushing to ramp up production. Congress has accelerated funding to buy more than 7,000 of the vehicles by early next year, and the military services are seeking some 21,000 in all, at a cost that could exceed $20 billion. Defense Secretary Robert Gates has declared his determination to "produce as many of these vehicles and get them into the field as fast as possible," though the precise number needed has yet to be established.

Unfortunately, the MRAPs will remain vulnerable to the deadliest I.E.D.'s, known as "explosively formed penetrators," which destroy vehicles from the side. The military is looking for ways to add armor to the MRAPs and is testing another new vehicle to counter that threat.

If the small companies that make these vehicles are not able to produce the quantities needed quickly, President Bush and Secretary Gates ought to make this a crash program and enlist major manufacturers.

There can be no excuse for failing to provide the best possible protection for American troops in this disastrous war.