Strela

Reports indicate three U.S. helicopters have been shot down in Iraq this past week. The method used has not been clearly elaborated, but it's possible that ground-air Strela-type shoulder-fired missiles are being introduced into this scenario.

If so, then they will be coming from Russia, via Iran. The Russians defend their sale of "defensive rockets" to Iran as legitimate. Legitimate or not, it would be ironic payback for U.S. support of the Mujahadeen in the Russo-Afghan war, where the U.S. introduced Stinger (air-to-ground) missiles to help shoot down Soviet helicopters.

Payback is a bitch.