Arming the insurgency

Who's arming the Iraqi insurgency? For the past year, the US has been pointing the finger at Iran as part of its efforts to prepare the ground for a bombing campaign. But it seems that the Iraqi resistance's biggest source of weapons is... the US. A report [PDF] from the Government Accountability Office has found that the Pentagon cannot account for more than half the weapons supposedly delivered to Iraqi forces - including 110,000 AK-47's and 80,000 pistols. I'm sure the resistance are finding them very useful.