In the last three years, American infantry in Afghanistan, going out on foot patrol, have been encountering more IEDs (Improvised Explosive Devices, usually mines or bombs left in buildings or at the side of roads or trails). In 2009, troops encountered no IEDs while on foot patrols. But last year, nearly a thousand were encountered, and that number appears to be doubled this year. Troops on foot have several advantages over those in vehicles, even those in MRAP (Mine Resistant Ambush Protected) armored trucks. For one thing, the foot troops can avoid trails. That's sometimes difficult in Afghanistan, and that's when you have to pay close attention to any IEDs on the trail. But that's where infantry have another edge, they are moving more slowly, and are accustomed to constantly, and closely, scrutinizing, their surroundings. As a result, foot troops spot, and avoid about 80 percent of the IEDs they come across, compared to half that rate for those in vehicles.
Increasingly, IEDs are being placed in buildings. This is usually the case when civilians have fled their walled compound when the Taliban showed up, and then the Taliban ran off when they found out that NATO troops were approaching. In some cases, once NATO engineers have checked out the IED filled compound, the place is blown up, and NATO pays to build a new one, because it would have been too dangerous to clear out all the IEDs by hand.
In any event, so far this year, the Taliban appear to have shifted their main effort from IEDs to suicide bombers. This is another way of admitting they are losing. In the last few months, NATO troops have been discovering most of the IEDs planted in their way. Partly this is because NATO troops have been moving deeper into areas long controlled by the Taliban, and this is forcing the enemy to use all available resources (and all the IEDs they have) to try and stop the advance.
Moreover, using tanks and MRAPs, the mines and bombs that do go off are causing fewer troop casualties. The infantry aren't as bombproof, but they do spread out while on patrol, thus limiting casualties when an IED does go off. But civilians are not so fortunate, which has led to more tips from civilians about who is building and placing the bombs, and where the bombs are being built. With so many bomb builders dead or arrested, and their workshops destroyed, the roadside bomb campaign is seen as a waste of effort. This is especially true because the growing military pressure on the heroin gangs has reduced the amount of cash the Taliban can obtain for "protecting" the gang operations (growing poppies, which produce opium, and then turning that into heroin in crude chemical labs, and then smuggling the heroin out of the country.)
It's the NATO troops coming at them on foot that the Taliban fear most. Thus the Afghan landscape is filling up, again, with buried explosives. The landmines are the worst, because they go off automatically. Most IEDs are detonated by wire or wireless commands. The problem for Afghanistan is that, even after the Taliban are gone, a lot of these IEDs, meant for NATO infantry that never showed up, will still be out there killing civilians.