Missed this a couple of days ago:

Two weeks ago, the Bush administration organized an intelligence briefing for journalists in Iraq to demonstrate that Iran was providing weapons to Iraqi insurgents. According to the anonymous briefers, the weapons -- particularly explosively formed penetrators or E.F.P.s -- were manufactured in Iran and provided to insurgents by the Quds Force -- a fact that meant direction for the operation was “coming from the highest levels of the Iranian government.”

Well. A raid in southern Iraq on Saturday seems to have complicated the case. There, The Wall Street Journal reports (sub. req.), troops "uncovered a makeshift factory used to construct advanced roadside bombs that the U.S. had thought were made only in Iran." The main feature of the find were several copper liners that are the main component of EFPs. But, The New York Times reports, "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."

Among those cloudy items 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."