This feature is from award-winning journalist Stephen Grey on his Dispatches programme America's Secret Killers
It involves an ultra-secret force described by one Pentagon adviser as an 'industrial scale counter-terrorism killing machine', and it's transforming the war in Afghanistan.
In America's Secret Killers, we investigate America's Kill-Capture campaign – an incredible blitz of raids and airstrikes that has killed over 3000 Taliban fighters in the last year and captured at least 8000.
Working with British special forces such as the SAS and SBS, the mission is being led by the US Joint Special Operations Command (JSOC) - the elite force whose soldiers killed Osama bin Laden.
In Afghanistan, while the public image of the war is often of a 'hearts and minds' campaign led by regular troops to win over the Afghan population, we found that in reality the military, under pressure for rapid results, is increasingly pinning hopes on its more secret and controversial operations.
The film is the result of six months of top-level access to NATO commanders and soldiers and to those involved with Special Forces. Filming and reporting took place on both sides of the front line, with soldiers and with the Taliban.
In our exploration of the war's secret heart, we came across some surprises, such as a special CIA armed force – dubbed a 'private army' by one US diplomat – that now patrols the border between Afghanistan and Pakistan. Or the discovery that Taliban prisoners are now being trained and used to study satellite photos and help pick targets for drone attacks.
But there are many who question the overall direction of the strategy. Afghan politicians told us the Kill-Capture campaign results in the death of too many innocent civilians and they criticise the invasion of Afghan homes by 'night raids' as a violation of Afghan culture. But, despite the public criticism, we found JSOC was conducting some 200 such night raids a month – six-times the number of two years ago.
Last week, the Afghan president, Hamid Karzai, gave the NATO coalition a 'final warning' to end attacks on Afghan homes with airstrikes and raids. And he threatened that if he was ignored, the Afghans would 'deal with occupying forces' as they have in the past.
General David Petraeus, the US and NATO commander in Afghanistan, told me these targeted raids were an essential part of a mix of tactics. 'When you're faced with a serious, deteriorating situation, you have to do something about it. And the best way is to use every tool available to you,' he said.
According to Petraeus and his advisers, the medicine is starting to work. The Taliban is on the run and getting desperate.
But is the Kill Capture campaign hitting the right targets? And with British and American troops now approaching almost 10 years of fighting in Afghanistan, how much does it really help in winning the war?
When Dispatches examined the case of one killing – a military assassination by airstrike of an alleged senior Taliban leader – we found disturbing evidence that JSOC may have killed completely the wrong man.
Whether on target or not, some critics also question if killing the Taliban's top leaders may simply cede power to new generation of extremists who will kill more innocents – and will have no interest in finally agreeing to make peace and end this long-running war.
Filming in northern Afghanistan, where US special forces have wiped out a succession of top Taliban leaders, our team set out to meet some of their replacements. We found the Taliban there under extreme pressure, but also confident in their own resilience. 'This war has become like delicious food for us,' one leader tells us. 'When a day passes without fighting, we get restless.'
You can follow Stephen Grey on Twitter: @StephenGrey