One of the reasons that the number terrorist suicide bomb attacks, and casualties, are occurring at a lower rate in Afghanistan, compared to Iraq, is that there is better technology available to detect suicide bombers (on foot or in vehicles). U.S. troops have the highest detection rate, but now the American "magic" is being transferred to the Afghan security forces, who actually man most of the checkpoints and roadblocks. As the U.S. trains Afghan police and soldiers to better handle terrorists, the Americans provide many U.S. techniques and technologies as well. The Afghans are often amazed at how effective the U.S. troops are, and some of this performance is due to technology the Afghans don't have. So the U.S. has to buy some of the high tech tools for the Afghans.
One of the more recent purchases is 300 Fido XTi explosives detectors. This 2.7 pound device can detect explosives with the same accuracy as a dog. These electronic devices are expensive, at about $22,000 each, but they are small enough to mount on a robot, or, via a cable, a safe distance from the troops. Fido XT first showed up in the combat zone four years ago, and has a good track record. But an expensive device like this is more than the Afghans can afford. So the U.S. buys them for the Afghans, and everyone benefits because of the bomb attacks that are foiled, and the bombers who are taken alive, and interrogated to find the permanent (and difficult to replace) members of the bomber team.