Countrywide, the most frequent cause of troop deaths has been what the military calls improvised explosive devices, typically containers packed with rudimentary ingredients found on many farms, like nitrate-based fertilizers, diesel fuel, aluminum shavings or kitchen ingredients.
These homemade explosives are buried along roads traveled by Western military forces. They are often activated when the weight of an armored vehicle — or sometimes just a soldier or a Marine walking overhead — squeezes together a trigger consisting of two buried slats, which closes a circuit that detonates the bomb. Despite their basic construction, many of these bombs are powerful enough to rip open more lightly armored coalition troop carriers.
It is highly problematic for NATO forces that these bombs are so easy to manufacture. Unlike the Viet Cong, the Taliban insurgents have no impressive benefactor providing them with the weaponry to engage us in combat. Through the use of these bombs, however, they can kill Americans without even firing a single shot.