When British troops in Helmand need air support, it doesn't only come from airfields within Afghanistan itself - it may come from a floating runway 500 miles away.
That runway is a US Navy aircraft carrier in the Arabian Sea, currently the massive USS Abraham Lincoln.
Over the last few months its 65 aircraft have undertaken up to 30 missions a day.
"Over 75% of the close air support missions we have flown from the carrier in the past three months have been in direct support of the UK Marines and forces in Helmand province," says Rear Adm Mark Guadagnini, commander of Carrier Strike Group Nine, the small armada of US warships operating in the region.
The USS Abraham Lincoln is the centrepiece of the fleet.
"We are the mobile artillery for the coalition forces," says Adm Guadagnini.
Spotting roadside bombsLt Sarah Abbott, an F-18 pilot, described one air strike, with a laser-guided bomb.
"I was engaged with the J-TAC, the guy on the ground who is the air controller. And we were in support of a troop in contact situation," she recalls.
"They were taking fire from an insurgent position, and we were called in to take out that insurgent position."
This is a classic case of air support for ground troops. But a surprising number of people on the USS Abraham Lincoln emphasise the care with which destructive force is now used.
This follows devastating mistakes by US and other Nato forces, in which Afghan civilians died, with deeply damaging consequences for the Western effort.
