PBS FRONTLINE: RUMSFELD'S WAR PART 3 OF 5

"I think to a degree, he's stubborn. Being stubborn, holding to your convictions is good to a point, but when the evidence around you indicates your position is not tenable, then you ought to start adapting to the situation," says retired USMC Lieutenant General Paul Van Riper.

That stubbornness, some officers say, led Rumsfeld to put the military in the difficult position of fighting in simultaneous conflicts against an unconventional enemy. With mounting casualties in Iraq and without a clear exit strategy in either Iraq or Afghanistan, Rumsfeld's critics charge the secretary has pushed too far. The danger, they say, is a military incapable of effectively fighting the next major conflict.

Former CENTCOM Commander-in-Chief General Joseph Hoar (Ret.) tells FRONTLINE, "Today we find over fifty percent of the United States Army, the regular army, ten divisions, committed overseas. It's not sustainable."

Rumsfeld, however, has stood firm in his assessment that U.S. fighting forces are more than capable of handling these or future conflicts, recently telling the U.S. Senate Armed Services Committee that with over 2.5 million Americans already enlisted, the military's problem is management of resources, not recruitment.