Lethal Weapons

Low-tech arms and loose networks trip up the world's most sophisticated fighting force.

For the U.S. military, the Iraq war has settled into a deadly learning cycle. As soon as U.S. troops develop counters to insurgent weapons and tactics, insurgents come up with something new so Americans must again adapt.

Both President Bush and Maj. Gen James Simmons, deputy commanding general of support for U.S. forces in Iraq, recently used the term "thinking enemy" to describe America's foes. Their attacks display a startling degree of innovation, indicating they are growing more, not less, capable. In recent weeks, the U.S. military has sounded the alarm over shaped-charge bombs capable of penetrating even the most heavily armored vehicles. More and more helicopters are being shot down. In late February, insurgents launched a concentrated attack against a remote U.S. outpost north of Baghdad. And they have detonated bombs stacked alongside chlorine gas cylinders to produce crude chemical weapons.

Iraqi fighters have stymied the world's most technologically advanced military with relatively low-tech arms looted from Iraq's many weapons depots and augmented by off-the-shelf technology. "Our opponent uses Radio Shack as his procurement system," said retired Army Gen. Montgomery C. Meigs, director of the Pentagon's Joint Improvised Explosive Defeat Organization, during a September 2006 briefing in Washington.

New tactics, shared and debated online in chat forums dedicated to battlefield lessons learned, spread rapidly across different guerrilla groups and networks, says Peter Harling, a senior analyst with the Brussels-based International Crisis Group, who has translated insurgent manuals and Web sites. Former Iraqi military officers provide online advice about mounting sniper attacks and the best methods for attacking convoys and shooting down helicopters, often with accompanying video of successful attacks. Over the past year, insurgent discussions have focused on developing tactics and procuring weapons to shoot down U.S. helicopters. The recent "spike in attempted shootdowns" is of major concern to senior U.S. commanders, says Marine Corps Commandant Gen. James T. Conway, as it "represents an intensity of effort that we haven't seen in the past."

Most such attacks use the old Russian-built shoulder-fired SA-7 missile, Conway says, which can be defeated by electronic countermeasures on U.S. helicopters.

The SA-7 is effective only against slow-moving or hovering helicopters. "We lost a Cobra outside Fallujah to an SA-7 because it was hovering and firing, and the systems didn't have time to actuate before the missile got to the aircraft," he says. More threatening are next-generation anti-aircraft missiles such as the SA-16 and SA-18 now appearing in Iraq.

In 1986, the Afghan mujahedeen used advanced Stinger anti-aircraft missiles to defeat the Soviet Army by forcing pilots to fly at much higher altitudes, thereby robbing troops on the ground of the close air support that had tilted battles in their favor. The same could happen in Iraq, where workhorse helicopters used to move vast quantities of troops and materiel are as vital to American operations as they were in the Vietnam War. Helicopters already operate under strict rules to ensure their safety and prevent downed pilots from being captured by insurgents. In December 2005, a young platoon leader in Iraq told of calling for help from helicopters overhead during a firefight only to be refused because the rules precluded the aircraft from flying above enemy fighters.

Iraqi insurgents have proved most creative in devising roadside bombs. They initially used cell phones and hand-held radios to trigger the bombs. Then the U.S. military fitted its vehicles with radio frequency jammers. Now, insurgents reportedly use non-jammable hard wires to detonate the devices. When the United States added more armor to vehicles, insurgent bombs grew bigger.

Urban Roadside Bombs

A particularly lethal roadside bomb, called an explosively formed penetrator, is capable of piercing the most heavily armored vehicles, military officials say. On Feb. 11, U.S. military and intelligence briefers in Baghdad said Iran was supplying the bombs to Iraqi insurgents. They said the bombs, which use an explosive charge to shape a copper disc into an armor-penetrating slug, were first used against American troops in May 2004, and EFP attacks have doubled during the past year.

The most devastating roadside bombs in Iraq have been placed on rural dirt roads, where insurgents could bury enormous devices. But on paved roads in Baghdad, insurgents' bomb size is limited. The high volume of traffic and frequency of American patrols meant bombs had to be hastily placed or kicked out of a car. They couldn't be buried, so they had to be small. The EFP-a small, compact, armor-penetrating bomb-is tailor-made for urban areas.

It's not clear whether, as U.S. officials assert, only Iran could have supplied the technological expertise to make the EFPs now appearing in Iraq, or whether the bombs were smuggled only to Shia militia groups allied with Iran.

In January 2005, a U.S. military intelligence officer in Baghdad said Sunni insurgent groups in west Baghdad were using a new type of roadside bomb, identified at the time as a "platter charge." In December 2005, high-ranking military and intelligence sources in Baghdad discussed the EFP threat in detail and said the devices were being manufactured by insurgent groups in machine shops in Iraq. They said a small batch of EFPs using commercially available infrared triggering devices and battery packs were intercepted in southern Iraq in mid-2005. Sunni insurgents in Baghdad then began using crude knockoffs of these EFPs, which were manufactured in Iraq.

The U.S. military is rushing to Iraq new EFP-defeating armor kits to outfit Humvees. But military sources say even the added armor might not be enough.

The wars in Iraq and Afghanistan have shown that in today's open-source, highly networked world, no single nation or military has a stranglehold on the best tactics or weapons. "The [U.S.] Army likes to say they have the best training facilities in the world," says Andrew Krepinevich, executive director of the Center for Strategic and Budgetary Assessments in Washington. "Quite frankly, the Iraqi insurgents are at the world's best [training center] right now-they're there 24 hours a day 365 days a year, going up against the world's best."