At a cost of $1 million each, the ugly tan beasts known as MRAPS have saved countless lives and absorbed or deflected thousands of insurgent bomb blasts in teeming cities, desert flats and rutted mountain roadways. The lumbering vehicles are so beloved that soldiers have scrawled notes of thanks on their armor.

So why would the U.S. military suddenly start chopping up as many as 2,000 of the vehicles and selling them as scrap? After all, just six years have passed since high-tech MRAPs were developed and 27,000 of them cranked out and shipped in a $50-billion production blitz.

As it turns out, the Pentagon produced a glut of the mine-resistant, ambush-protected trucks. The military brass has now calculated that it’s not worth the cost of shipping home damaged, worn or excess MRAPs to bases already deemed oversupplied with the blast-deflecting vehicles.

As they are “demilitarized,” many of the MRAPs are sold as scrap metal to eager Afghan buyers.

It costs about $12,000 to crunch and dispose of a single MRAP here, said Mark E. Wright, a Defense Department spokesman. To ship one back to the U.S. and rebuild it to current standards would cost $250,000 to $450,000, he said. Selling the vehicles as scrap instead of shipping them home and refitting them will consequently save about $500 million, Wright said.