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.
As in Iraq, Taliban insurgents are constantly modifying their designs to stay one step ahead of detection including disrupting radio signals that can detonate IEDs by remote control.
"You can't buy an IED," said a security company executive in Kabul. "The Taliban will use whatever they can to make a bang and cause problems."
NATO issues almost daily reports on IED deaths, principally in southern Taliban strongholds but increasingly in previously peaceful provinces.
The bombs cause horrific injuries to survivors -- blowing off limbs, shredding torsos after cutting through military vehicles and body armour worn by soldiers and journalists who travel with them.
Western governments spending billions to support the Afghan government have highlighted IEDs as the biggest challenge facing troops deployed to Taliban hotspots, especially in southern Helmand and Kandahar.
So far this year, more than 300 foreign troops have died in Afghanistan, according to the independent icasualties.org website, making 2009 the deadliest year of the eight-year war.
By August last year, IEDs accounted for 75 percent of all "enemy initiated action" in Afghanistan, according to the Pentagon's Joint Improvised Explosive Device Defeat Organization (JIEDDO) set up to tackle the scourge.
The high casualty figures have seen US and British public approval for the war plunge as politicians and military leaders scramble for new ideas to combat the resurgent militants.
The expert deployment by the Taliban of unconventional weapons has stymied international forces, still waging conventional warfare, said a former US army officer who spoke on condition of anonymity.
"The enemy is adapting and evolving faster than (Western forces) can keep up and so the Americans and Brits are forced to literally inch forward in their operations to take territory from the bad guys because those roadside bombs could be buried anywhere," he said.
Countering IEDs is part of the new strategy put forward by the commander of US and NATO troops in Afghanistan, General Stanley McChrystal, in a review of the Afghan war handed to his superiors last week.
British Prime Minister Gordon Brown on Friday said, "Offensive operations are focusing
more on countering the IED threat".
In a speech in London, Brown said foreign troop deaths "are almost twice as high as this time last year, and three quarters of these are now due to IEDs".
"Having failed in 2006 and 2007 to defeat international forces by conventional means, the Taliban have more than doubled their IED attacks over the past year," he said.
"Already this year we have deployed 200 specialist counter-IED troops" to Afghanistan, he said.
"We are sending another 200 specialist forces and new equipment to find and defuse the IEDs and identify and target the networks who lay them."
McChrystal is expected to request more US troops for deployment to Afghanistan by the end of the year, to accelerate training of Afghan forces as well as specialists in IEDs, which include vehicle bombs and suicide car bombs.