But while the find gave experts much more information on the makings of the E.F.P.’s, which the American military has repeatedly argued must originate in Iran, the cache also included items that appeared to cloud the issue.UPDATE: Paul Kiel at Muckraker has a good post on this topic.
Among the confusing elements were cardboard boxes of the gray plastic PVC tubes used to make the canisters. The boxes appeared to contain shipments of tubes directly from factories in the Middle East, none of them in Iran. One box said in English that the tubes inside had been made in the United Arab Emirates and another said, in Arabic, “plastic made in Haditha,” a restive Sunni town on the Euphrates River in Iraq.
....That raised the possibility that the parts were purchased on the open market and that the [copper] liners were then manufactured to the right size to cap the fittings.
Paul quotes the Wall Street Journal (sub required) thusly, "[Troops] uncovered a makeshift factory used to construct advanced roadside bombs that the U.S. had thought were made only in Iran."
And on the topic of the origin of the copper caps, the First Cav captain who conducted the raid, "Capt. [Clayton] Combs said the copper caps were smooth and perfectly symmetrical, suggesting they had been made with a high degree of technical precision. He said he didn't know where the caps came from or whether they had been made in Iran. "That's the hard thing about this war," he said."