May 21,2008: In the last two months, Iraqi and American forces have largely destroyed the Iran backed Mahdi army in Basra and eastern Baghdad. In the process, a lot of Iranian weapons and incriminating weapons have been captured. It's pretty clear that the Iranians are supplying pro-Iranian Iraqi Shia militias with cash, weapons and technical advisors. Particularly worrisome are the Iranian explosively formed penetrator (EFP) weapons. While Iran stridently denies sending these to Iraq, they have long advocated the use of this specialized weapon. Iranian supported Hizbollah, in Lebanon, has long used EFP against Israeli troops.

As the Sunni Arab terrorists were defeated last year, and attention turned to the Shia militias (like the Mahdi Army), the number of American casualties from EFPs increased. Last year, about five percent of the Coalition combat deaths in Iraq, and about eleven percent of those killed by roadside bombs, were because of EFPs. This year, that percentage has increased, but not that much, because of the increased use of more heavily armored vehicles (like MRAPs).

The EFP is nasty because it can penetrate the armor on just about anything but an M-1 tank. An EFP is a precision weapon, not an ad-hoc assemblage of explosives (like most roadside bombs). Your typical EFP is a cylindrical device, the optimal one often described as similar to a coffee can. But the cylinder metal must be thicker. You fill about 60 percent of the "coffee can" with explosives (C4, also known as plastique will do). Then you insert a detonator on the closed end of the "coffee can" and a concave copper plug that is pushed into the plastic explosive. The tricky part here is that the depth of the concave copper part, and the thickness of the copper, have to be just right. It requires someone expert at math and the chemistry of explosives to make those calculations. You can make a mould for casting the copper plug, but you must make sure you get the thickness just right. The more precisely the copper plug is made, and the EFP assembled, the more armor the device will penetrate, and the more damage it will do inside the target vehicle.

You set EFPs off with the detonator, either via wire, or wireless, connection. When the C4 explodes, it forms the copper cap into a blob of molten copper, moving faster than a speeding bullet (about 1,500 meters a second). The blob stays intact, and lethal, for a few hundred meters, traveling pretty much in a straight line. However, the EFP is still difficult to aim. The user has to place it so that, when it goes off, it will hit a vehicle sitting in a position the user has already figured out. For this reason, EFPs are usually set up at places where vehicles have to stop.

When the EFP hits an armored vehicle, it burns and punches its way through the armor. Once inside the vehicle, it injures or kills whoever it hits, as well as igniting combustible material and generally scaring the hell out of everyone. The increased use of MRAP vehicles however, has meant that, while EFP attacks are up over a third this year, casualties from those weapons is down 17 percent.

EFPs weigh under ten pounds, are small and easily carried and concealed. They are quick to set up. Some appear to have been made in Iraqi workshops, in Shia parts of the country. These are crude, and much less effective. But most others appear to come from Iran, made in government factories that have long specialized in EFP manufacture. . Naturally, these "Iranian EFPs" don't have any distinguishing marks on them (indicating a state arms factory, or a "Made in Iran" label). The Iranians are not stupid, they don't want to admit supplying these weapons. But all indications are that, most EFPs are made in Iran. And their main purpose is to kill American and British troops, and cause more chaos in Iraq.

But with the battle against the Mahdi Army, Iraqi troops are getting killed. This led to a delegation of Iraqi politicians going to Iran to plead for a halt the flow of EFPs. The Iranians again denied everything, which led to more Iraqis seeing Iran as an enemy, not a fellow Shia state they could depend on.