Record number of U.S. troops killed by Iranian weapons

U.S. military commanders in Iraq say Iranian-made weaponry is killing American troops there at an unprecedented pace, posing new dangers to the remaining forces and highlighting Tehran's intensifying push to gain influence over post-U.S. Iraq.

June was the deadliest month in more than two years for U.S. troops, with 14 killed. In May, the U.S. death toll was two. In April, it was 11. Senior U.S. commanders say the three primary Iranian-backed militias, Kataib Hezbollah, the Promise Day Brigade, and Asaib al Haq, and their rockets were behind 12 of the deaths in June.

A detailed U.S. military breakdown of June's casualties illustrates the growing threat posed by Iranian munitions.

Military officials said six of the 14 dead troops were killed by so-called "explosively formed penetrators," or EFPs, a sophisticated roadside bomb capable of piercing through even the best-protected U.S. vehicles. Five other troops were killed earlier in the month when a barrage of rockets slammed into their base in Baghdad. It was the largest single-day U.S. loss of life since April 2009, when a truck bomb killed five soldiers. The remaining three troops killed in June died after a rocket known as an "improvised rocket-assisted mortar," or IRAM, landed in a remote U.S. outpost in southern Iraq.

U.S. officials say the EFPs, rockets, and IRAMs all come from neighboring Iran. Tehran denies providing the weaponry to Shia militias operating in Iraq.

"We're seeing a sharp increase in the amount of munitions coming across the border, some manufactured as recently as 2010," Maj. Gen. Jeffrey Buchanan, the top U.S. military spokesman in Baghdad, said in an interview. "These are highly lethal weapons, and their sheer volume is a major concern."

Buchanan said much of the current weaponry is passing into the country through its formal border crossings with Iran. Current and former American military officers claim that those border crossings are guarded by Iraqi security personnel whose long-standing financial relationships with their Iranian counterparts means they will accept bribes or turn a blind eye in order to allow munitions through.

Buchanan noted that in the last six months of 2010, there were no attacks involving IRAMs, which are typically constructed out of fuel or propane tanks loaded with large quantities of explosives and then powered by rockets. In the first six months of 2011, by contrast, there were at least seven such attacks, several of which resulted in American fatalities.

Such attacks are particularly worrisome to U.S. commanders because Iraq's overall level of violence-and the number of strikes directed at U.S. forces-is just a small fraction of their pre-surge levels. In 2007, there was an average of 145 attacks per day across the country. In the first six months of 2011, the average was just 14 per day, with six targeting U.S. troops.

Covert Iranian shipments of munitions into Iraq are not a new phenomenon, but Buchanan said the amount of weaponry being used against U.S. forces throughout the country has reached unprecedented levels. U.S. ground patrols have in the past suffered one or two EFPs in a single attack, but Buchanan said some recent incidents have involved as many as 14 of the powerful bombs. American bases, meanwhile, are being struck by dozens of rockets at a time. In mid-July, a single U.S. outpost was hit by 40 rockets, though none caused casualties, Buchanan said.

"The number of EFPs being used in a given attack, the number of rockets being launched in a single volley-all of that is much higher than in the past," Buchanan said.

The rising American death toll from Iranian-made weaponry provides a grim counterpoint to Iraq's escalating political debate over whether any U.S. troops should be allowed to remain in the country past the end of the year. Under the terms of a treaty signed by the Bush administration in late 2008, the remaining 46,000 U.S. troops now in Iraq are supposed to return home by the end of 2011. The Obama administration has made clear that it would be open to leaving approximately 10,000 troops in Iraq indefinitely if Baghdad requests such an extension, but the fractious Iraqi government has yet to decide whether or not it wants the troops to stay.

In the meantime, American influence within Iraq is on the wane. U.S. officials believe the Iranian government is trying to fill the void, stepping up both its commercial dealings with Iraq's government-the two countries, along with Syria, signed a $10 billion natural-gas pipeline deal earlier this week-and its covert support to the armed militias inflicting casualties on the departing U.S. troops.

"Their intent is to bleed U.S. forces on the way out of Iraq for some sort of moral victory, as well as to reestablish coercive control over Iraqi governors in the south by showing off their capacity to carry out these kinds of sophisticated attacks," said Mike Oates, a recently-retired, three-star Army general and former commander of all U.S. forces in southern Iraq. "They're trying to prick us as we leave."

U.S. military officials acknowledge that it will be difficult, if not impossible, to prevent Iranian-made weaponry from being smuggled into Iraq. "They've been smuggling things over that border for decades, if not longer," Oates said. "Trying to figure out how stuff moves into Iraq is like staring into dark water."

Finding weapons as they move across the porous and largely-unmarked border between the two countries is a major challenge. During his time in Iraq, Oates's forces received intelligence assessments suggesting that Iranian munitions were being smuggled in through southern Iraq's marshlands. American forces devoted considerable time to "scouring" the region, but didn't find the weapons, Buchanan said. Iranian smugglers were indeed using the marshes, but to sneak in prescription drugs and consumer goods like plates and cookware.

"There have been no reported incidents in which American forces have actually interdicted Iranian munitions while in transit," Oates said. "That should tell you something about just how hard this is to stop."