In this New Yorker article, Seymour Hersh lays out his theory on the Bush Administration’s plans for neutralizing Iran. As with most of Hersh’s work, it is a fascinating read. He concludes with the following story about tensions between Allied forces:

Another recent incident, in Afghanistan, reflects the tension over intelligence. In July, the London Telegraph reported that what appeared to be an SA-7 shoulder-launched missile was fired at an American C-130 Hercules aircraft. The missile missed its mark. Months earlier, British commandos had intercepted a few truckloads of weapons, including one containing a working SA-7 missile, coming across the Iranian border. But there was no way of determining whether the missile fired at the C-130 had come from Iranóespecially since SA-7s are available through black-market arms dealers.
Vincent Cannistraro, a retired C.I.A. officer who has worked closely with his counterparts in Britain, added to the story: ìThe Brits told me that they were afraid at first to tell us about the incidentóin fear that Cheney would use it as a reason to attack Iran.î The intelligence subsequently was forwarded, he said.
The retired four-star general confirmed that British intelligence ìwas worriedî about passing the information along. ìThe Brits donít trust the Iranians,î the retired general said, ìbut they also donít trust Bush and Cheney.î