Insurgents in Afghanistan have answered the Obama administration's troop surge with a surge of their own, planting thousands of roadside bombs that caused more U.S. troop casualties last year than the prior eight years of the war.
Since President Obama took office in January 2009 and vowed to end Taliban gains in Afghanistan, casualties from improvised explosive devices (IEDs) have nearly quadrupled.
In 2010, the bombs wounded 3,366 U.S. troops, which is nearly 60% of the total IED-wounded since the war's start in late 2001, according to Pentagon figures.
In nine years of war, 617 American troops have been killed by IEDs and the majority of those deaths came in the past two years. The 268 troops killed by IEDs in 2010 account for more than 40% of all deaths caused by bombs during the war.
"It's clear that the insurgency in Afghanistan remains very robust," said John Nagl, a former Army officer and president of the Center for a New American Security, a think tank in Washington. "As we increase our capabilities in the country and the region, they are also 'surging.' "
President Obama boosted troops levels in Afghanistan from 30,000 two years ago to the close to 100,000 troops there today. Fighting alongside U.S. troops are 50,000 international forces. There also are more than 200,000 Afghan army troops and police.
The U.S.-led International Security Assistance Force that oversees the war effort says the higher tolls are the result of the added troops moving into Taliban-held territory and forcing them to fight back. Those troops are often on foot patrol outside the protection of armored vehicles, the ISAF says.
Also contributing to the increase in IED casualties is that a relatively mild winter has kept mountain passes open and allowed insurgents to travel more freely. In a statement to USA TODAY, the ISAF said that al-Qaeda is directing militants to return to areas they were pushed out of by American and Afghan forces and fight back.
ISAF also said it is trying to reduce the IED threat by sending out teams of bomb hunters on foot and in vehicles to find and disable the devices. Cameras monitor routes to catch insurgents burying bombs, and Afghan forces are being trained to find IEDs, the ISAF said.
Despite increased casualties, the military says progress is being made against the IED threat.
The bombs, often made from cheap, easy-to-obtain ingredients such as fertilizer and fuel, have become less lethal in recent months, according to the Joint IED Defeat Organization, the Pentagon's lead agency for combating makeshift bombs. One quarter of IED attacks killed or maimed U.S. troops last summer compared with 16% of such attacks in December.
Wounded troops are less likely to die now as well. The ISAF attributes better survival rates to quicker medical treatment and the widespread use of Mine Resistant Ambush Protected trucks built specifically for Afghanistan's tough terrain.
Nagl foresees a tough fight ahead, since fighting tends to pick up each spring.
"My sense is that this struggle will continue deeper into the fighting season than usual, and I don't expect bad weather to stop us from pursuing the Taliban," Nagl said. "We'll know a lot more about how effectively we've been able to put pressure on the enemy based on who comes out to fight in the spring."