Cheap home-made bombs are exacting a high price from the world's most sophisticated armies battling Afghanistan's Taliban insurgency and have become the pivot on which the eight-year war is turning.
The weapon of choice is killing foreign troops in record numbers and pushing Western public support for the war in Afghanistan into reverse.
As Taliban tactics sow terror, the 100,000 international troops operating under US and NATO command and with Afghan forces, are struggling to adjust their strategy to take on the insurgents as their reach expands.
"The insurgents have moved to terrorist-style tactics because they realise the high pay-off of IEDs (improvised explosive devices) and suicide bombings," said General Jim Dutton, deputy chief of NATO forces in Afghanistan.
"This is a quick win for them and we are putting a lot of work into dealing with it," he said in a recent interview with AFP.
Experts say the bombs are cheap and easy to make, are rigged to timers or remote controls, can be detonated when vehicles drive over pressure plates and are increasingly linked into a chain of bombs to cause maximum damage.
Bomb-makers cannibalise mortar shells and old mines, which are easy to find in the war-ravaged countryside, or jerry-rig mobile phones to crude explosives such as fertiliser and diesel fuel, or batteries.
Roadside bombs were used to great effect by insurgents in Iraq, where the impact on morale was as devastating as the death toll.
