May 24,2008: The demise of al Qaeda in Iraq, and the shift to fighting Iranian backed Shia militias, has led to greater use ofIranian made explosively formed penetrator (EFP) weapons. 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 as much as expected, because of extra armor added to the sides of MRAPs (Mine Resistant Ambush Protected) vehicles.

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, a cylindrical device, that is 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.

By adding another two tons of side armor to an MRAP, most EFPs can be defeated, usually with fatal consequences to the attacker, who is quickly fired on by the troops in the MRAP, and other vehicles in the convoy. There are about 3,000 MRAPs in Iraq, and only about ten percent have the additional side armor. These up-armored models are used in areas most likely to encounter EFP attacks, and have contributed to reducing EFP casualties nearly 20 percent, even as EFP attacks have climbed nearly 50 percent in the last few months. The greater use of MRAPs has cut roadside bomb casualties by 40 percent this year, even though such attacks are up about ten percent.

Combat commanders believe that over a hundred American lives have been saved this year because of MRAP use, and the troops seem to agree. Morale is up now that roadside bombs, particularly EFPs, are less of a threat. During the first four months of this year, 162 U.S. troops were killed in Iraq.