Fertilizer Bombs Continue To Challenge U.S. Military

Hundreds of U.S. troops in Afghanistan have been killed by improvised explosive devices. The Pentagon spends billions trying stop IEDs, which cost only about $40 to make and are little more than plastic jugs filled with explosive ammonium nitrate fertilizer.

"What you're looking at is fertilizer with an accelerant which could be sugar or sawdust. The blasting cap is often fashioned out of a ballpoint pen or Christmas lights," military reporter Greg Jaffe told Here & Now's Sacha Pfeiffer.

The fertilizer is manufactured in Pakistan, and so far U.S. military officials aren't having much success at stopping its flow across the border into Afghanistan. An owner of one of the fertilizer plants in Pakistan says farmers need the fertilizer and the amount that falls into insurgents' hands is less than 1 percent of his production.