With little fanfare, America opens a new front in the war on terror

Largely unseen by the rest of the world, America has opened up a new military front in the so-called war on terror. From a warship off Yemen, and from a heavily guarded base in East Africa, the Pentagon is running the "Joint Task Force–Horn of Africa".

On a windswept ridge on an extinct volcano crouches a team of US Special Forces. Hunching against the wind, they peer through a small device on a tripod. "Laser on," shouts one. An invisible laser beam streaks across the desert valley, locking onto a distant target. Seconds later a pair of US Marine Harrier jumpjets scream in, release their bombs, and arc into the blue horizon. It is a training run for US special ops to hone the skills they learned fighting Al-Qa'ida in the mountains of Afghanistan.

Quietly, and with little fanfare, the Pentagon and the CIA have been building up a sizeable presence in Djibouti, the peaceful republic in the Horn of Africa. At an old Foreign Legion base in the former French colony there are now nearly 2,000 US troops, preparing to go on counter-terrorist missions. Armoured Humvee jeeps burst periodically from the gates, probing into the surrounding bush. Blackened helicopters with encrypted communications for special operations clatter above the camp then sweep low over the white-washed walls of Djibouti city and vanish towards the mountains.

A few miles offshore, sits the hi-tech warship USS Mount Whitney, the HQ and intelligence base for the JTF-HOA. The commander is Marine Major-General John Sattler. "We're here to stop this region turning into a haven for Al-Qa'ida," he says. When they lost their bases in Afghanistan, he explains, the Pentagon feared the terrorists would flee west to Yemen and East Africa.

So a task force was set up to react rapidly to reports of terrorist activity. His command covers seven countries, Sudan, Ethiopia, Eritrea, Djibouti, Yemen, Somalia and Kenya. So is he just watching, I ask him, or preparing to go in, guns blazing? "Direct action", in the Pentagon jargon, is the last resort, I was told.

The Pentagon would prefer to work with the countries in the region, training them to tackle terror and pooling their intelligence resources. Yemen is held up as a shining example of such co-operation. British and US special forces have been training Yemenis in counter-terrorism. But in Yemen, America has already taken the law into its own hands.

Last November, the CIA used Djibouti to launch an unmarked Predator drone over Yemen. Using co-ordinates phoned in from a Yemeni intelligence officer on the ground, the drone flew to a car carrying six Al-Qa'ida suspects, fired its missiles and destroyed the car. The drone returned to Djibouti. It would have been the perfect "deniable op", had the Pentagon not gloated over it so publicly.

The US has been accused of extra-judicial killing, targeting suspects without bringing them to trial. There have been no further US airstrikesbut officials told me privately that Somalia and Yemen remained prime candidates for such an operation.

"One of our aims is to make this is a hard place for Al-Qa'ida to work in." General Sattler says. But while Washington feels it is now taking the war on terror to the enemy, by having so visible a presence here, America may well be offering Al-Qa'ida a new and tempting target.

Frank Gardner is the BBC's Security Correspondent. His special report will be shown tonight on BBC2's 'Newsnight' at 10.30pm.