LAST NOVEMBER, during the heady days of Operation Enduring Freedom, the U.S. military dropped a 15,000-pound bomb known as a Daisy Cutter on Taliban positions in Afghanistan. The bomb flattened everything in sight for roughly 600 yards. But while the Daisy Cutter’s blast occurred above ground, generating an overpressure that caused most of the damage, many reporters described the bomb as a fuel-air explosive.

“That’s absolutely incorrect,” Robert Hewson of Jane’s Air Launched Weapons told me in an article I wrote then on the Daisy Cutter. “This bomb does not ignite oxygen, turning the air into fire.”