The Taliban believed that the roadside bomb (IED, or Improvised Explosive Device) was the key to victory in Afghanistan, and a wonder weapon that would succeed where other ideas had failed. This is unlikely, but this is what Taliban commanders have been telling their subordinates for the last few years. As a result, the ineffectiveness of the bombs last year is believed to be a major blow to Taliban morale. The Taliban have greatly increased the bombing effort in the last three years, based on the promise that it would drive the foreign troops away. In 2008, the Taliban planted 5,600 roadside bombs, and that increased to 15,000 in 2010. Thus in 2008, it required 21 roadside bombs (including anti-vehicle mines and suicide bombs) to kill one foreign soldier. Last year, it required 23. A disproportionate number of these deaths were among non-U.S. NATO troops, who did not have as many MRAPs, or counter-bomb technology that the Americans possessed.
NATO and American troops encountered 457 bombs a month in 2008 and 1,250 in 2010. This is still much smaller than Iraq at its peak, where over 2,500 of these bombs were being encountered each month in 2007. As in Iraq, most of the bombs in Afghanistan are detected before they can be used, or otherwise neutralized (often with electronic jammers, or by catching and killing Taliban as they try to plant the bombs.)
The U.S. and NATO troops have several ways to limit the effectiveness of these bombs. For example, there are now nearly 10,000 MRAPs in Afghanistan now (about the same number in Iraq at its peak) The current number of MRAPs cut current U.S. and NATO casualty rates by 20-30 percent. NATO casualties in Afghanistan are already lower than those in Iraq, which are, in turn, only a third of the casualty rates in Vietnam and World War II.
The U.S. developed intelligence and surveillance techniques in Iraq that predicted where bombs would be placed, and found them before they could be detonated. That, plus the MRAPs for troops who do get hit by a bomb, will keep the U.S./NATO casualties down. U.S. troops have transferred their Iraq counter-IED (Improvised Explosive Device, or roadside bomb) techniques and technology to Afghanistan.
Meanwhile, the Taliban found that they were not as good at this IED stuff as the Sunni Arab terrorists in Iraq were. But since the Taliban can't do much damage in a direct confrontation with Western troops, and take heavy casualties when they try, roadside bombs are their most effective tactic. But in Iraq, the bomb strategy only worked because the terrorists had lots of money, and Saddam era explosives, to hire the bombers and make the bombs. In Afghanistan, the Taliban got funded by the drug gangs, who don't appreciate Western soldiers busting up heroin operations. Gang money pays to import large quantities of explosives (in the form of nitrogen based fertilizer, which is easier to get into Pakistan). But even with all those bombs, the death rate of Western troops is a third of what it was in Vietnam, where roadside bombs caused only 14 percent of the deaths. In Afghanistan, it's between 50-60 percent. Hiding from the enemy and blowing holes in roads didn't work in Iraq, and it's not working in Afghanistan either.
The protection for Western troops is not cheap either. MRAPs cost about five times more than armored hummers or trucks. The MRAPs are more expensive to operate, and less flexible than the hummer. MRAPs use a capsule design to protect the passengers and key vehicle components from mines and roadside bombs.