Tuesday, October 02, 2007

Fighting Roadside Bombs: Part II

This post continues my coverage of Rick Atkinson's series on the IED challenge and the U.S. military. In his second article Atkinson elaborates in some detail Defense Department efforts to counter the increasingly deadly effects of the IED threat to U.S. forces in Iraq.

Eliminating the IED problem was given top priority, although Atkinson argues that most of the various programs to combat the scourge were mostly ad hoc and unsuccessful. Atkinson also notes a particularly troubling development in the last couple of years involving newer explosive devices supplied to insurgents through the Iranian arms pipeline:

More than 250 American soldiers would be killed by another type of IED that was spreading across the battlefield and against which even the best jammers proved useless.

The first confirmed EFP -- explosively formed penetrator -- had appeared in Basra on May 15, 2004, and [Pentagon IED Task Force director Joseph] Votel had briefed Vice President Cheney in late June on the phenomenon, using a model to demonstrate how it worked. The weapon, which fired a heavy copper disc with devastating impact, typically used a passive infrared trigger that detonated the bomb when a sensor detected radiation from a warm passing object, such as a Humvee. Because no radio waves were involved, jammers had no effect.

A Defense Intelligence Agency weapons team had noted in the late 1990s that EFPs with infrared triggers were used by Iranian-backed Hezbollah forces against the Israelis in southern Lebanon at least as early as 1997. The few EFPs that were in Iraq during the early summer of 2004 invariably appeared in Shiite-controlled areas near the Iranian border, such as Basra and southeast Baghdad. That suggested "international linkages" to Iran, Votel told Cheney.

A colonel at the Israeli Embassy had repeatedly warned the task force about infrared-triggered EFPs. "He and other Israelis were pounding on the desk, saying, 'Listen, we've already been through this historically. This is what's going to happen next,' " a task force officer later recalled....

By early 2005, what one officer had described as "an ominous thing on the horizon" was moving to the foreground in Iraq. Most EFPs were built with several pounds of pure copper, either milled or punched with a 20-ton hydraulic press into a concave disc with a 140-degree angle, two to 11 inches in diameter. Triggered by the infrared sensor, a blasting cap in turn set off explosives packed behind the copper disc -- known as a liner -- inside a steel or plastic pipe. The detonation wave, moving at 8,000 meters per second, struck the liner, which inverted into a tadpole-shaped slug.

An EFP eight inches in diameter threw a seven-pound copper slug at Mach 6, or 2,000 meters per second. (A .50-caliber bullet, among the most devastating projectiles on the battlefield, weighs less than two ounces and has a muzzle velocity of 900 meters per second.) Unlike an armor-killing shaped charge, the EFP warhead did not turn into a plasma jet, but remained semi-molten. Copper was preferred because it is ductile and malleable, and does not shatter like steel. Typically fired at ranges from five to 10 meters, the slug could punch through several inches of armor, spraying metal shards across the crew compartment....

Debate intensified within the U.S. government over Iran's role in distributing EFPs. [General John] Abizaid was skeptical until British troops reportedly captured a cache of copper discs along Iraq's southeastern border. Other evidence accumulated. For example, according to a former DIA analyst, the C-4 plastic explosive found in some EFPs chemically matched that sold by Tehran's Defense Industries Organization and identified by specific lot numbers. Intelligence also indicated the Quds Force of Iran's Islamic Revolutionary Guard Corps was training and giving explosives to certain Iraqi Shiite groups, a senior DOD official said.

Read the whole thing. Abizaid counseled against military action to stop Iranian arms shipments to Iraq, arguing that "You know they're doing it, but you don't know that you want to go to war over it."

There's been some suggestion that Iranian-supplied munitions account for 70 percent of current U.S. casualties in Iraq. It seems to me, contrary to Abizaid, that this is something we'd want to go to war over.

For the previous post from this series, click here.

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