Iraqi troops fighting alongside Americans set the GIs up, in an incident last January. Five Americans were killed. The attackers were helped by Iranian forces:

The investigation reveals several new details about the assault, including:

•Iraqi police suddenly vanished from the government compound before the shooting started.

•Attackers, evidently briefed on how U.S. forces would defend themselves, bottled up more than three dozen soldiers in a barracks and headquarters complex using a combination of smoke and fragment grenades and satchel charges to blow up Humvees.

•Gunmen knew exactly where to find and abduct U.S. officers.

•Iraqi vendors operating a PX and barbershop went home early.

•A back gate was left unlocked and unguarded.

This is salient, it seems to me:

It's worth noting that Army officials disclosed none of this when Brig. Gen. Kevin Bergner, a former White House aide, briefed the press this month. Bergner failed to mention that an internal Army investigation had found that the Iraqi police the US troops are supposed to be training and cooperating with played a direct role in the ambush.

Instead, Bergner blamed Iran. "The Quds Force, an elite unit of Iran's Islamic Revolutionary Guards, helped plan and direct it with Iraqi militants, said Brig. Gen. Kevin Bergner, a military spokesman," USA Today reports.  "The Quds Force, he said, supplied Shiite militias with weapons and up to $3 million a month in aid."

Most lies in wartime are designed to trick the enemy. Bush's lies of omission are designed to trick the American people. If you can blame it all on Iran, you don't have to concede the fact that Iraq's military forces and police are extensions of sectarian militias. That would be off-message. Grrrr.