The Pentagon and the CIA have opened up a new front in the war on terror. It is not in the Gulf, but in the Horn of Africa.
US troops opening a new front in the War on Terror
From a hi-tech command ship in the Indian Ocean and a secretive base in Djibouti, Washington is collecting information on al-Qaeda and preparing to mount covert operations against its operatives in seven countries.
Djibouti is a funny place to fight a war from.
Its whitewashed streets carry no hint of menace.
The US military are almost nowhere to be seen. In smart cafes in the central square there are bistro tables and tottering chairs.
French gendarmes in khaki shorts sip cafe au lait and tap their cigarettes.
"Psst, monsieur!" calls a boy standing in the shadows with yesterday's paper and a packet of Gauloise cigarettes.
A man on crutches has his hand outstretched.
Here comes a posse of sailors, disembarked from France, all tattoos and jaws, just slightly drunk.
Tanned legionnaires with shaven heads prop up the bar and stare straight ahead. A man sits alone by the gates to the mosque, clutching the Koran with a withered hand.
I came here to see for myself how the Pentagon was fighting its so-called "war on terror".
Close to the main airport I knew it had set up a camp for nearly 2,000 troops. The idea, I was told, was to stop al-Qaeda members from making themselves at home in this region.
I asked to be shown how this is done, and the US military obliged.
The unspoken fear was that al-Qaeda would target this camp - but, today, they would certainly have been outgunned
In a swirl of dust, the helicopter put down in the shimmering heat. We filed on, into the tomb-like interior. I found myself sandwiched, as if under arrest, between two huge US marines, weighed down with rucksacks and weapons.
The aircrew gestured amidst the clatter of rotor blades, all goggles and jumpsuits and colourful patches. We took off, skimming over rooftops and a camp for Somali refugees.
The coastline of Djibouti slid past through the window - a beach, a mangrove swamp, a black volcanic mountain. We headed north, towards the Eritrean border.
Danger on the ground
The marines were to pitch camp on a deserted hilltop, preparing to test their weapons on some abandoned tanks. But when we touched down on the rocks, it seemed someone was expecting us.
There was a flash and a loud bang. The soldier opposite me tugged on his flak jacket, and grabbed his M16 rifle. Someone shouted "Incoming".
This was like a remake of Hollywood's Blackhawk Down, only for real. Suddenly I did not want to be there. But as fast as it began, the drama was over.
It turned out it was just an anti-missile flare, set off by a clumsy co-pilot as we landed.
On the barren hilltop, we spent an uncomfortable night. The burnt, volcanic rock made for a poor bed, and soon a tearing wind got up, tugging insistently at our sleeping bags.
A marine on radio watch called out all night: "Fireball one zero, fireball one zero. Do you copy, over?" I cursed him quietly, then realised it was already dawn.
A sad, grey light washed over the encampment. A patrol came in, exhausted, after keeping watch all night.
I could see no sign of life for miles around, but I was told there were smugglers and bandits who pass through the valley below.
The USS Mount Whitney is a state of the art command ship
The unspoken fear was that al-Qaeda would target this camp. But, today, they would certainly have been outgunned.
Out of the morning mist came a brace of helicopters, spewing rockets and cannon fire. The valley floor erupted in smoke.
The tank targets, I have to say, looked remarkably unscathed. But then came Harrier jumpjets, their bombs guided onto target by lasers aimed by the marines on the hilltop.
It was all very impressive but - I could not help thinking - slightly irrelevant for tackling an enemy, that rarely, if ever, shows itself.
Floating nerve centre
Airborne again, and this time the helicopter took me due east, flying fast and low out over the Gulf of Aden, skirting the coast of Yemen.
We circled twice over a solitary ship, tilting so steeply I found myself looking vertically downwards at the sea. This was the USS Mount Whitney, the nerve centre of the Pentagon's whole counter-terrorist operation in the region.
On deck, through a bulkhead and down a steel corridor, I was ushered in to meet the two-star general in charge.
Major-General John Sattler is all marine. Tanned, fit and 50, he had a handshake which would crush a billiard ball.
He smiled a lot, then told me the al-Qaeda threat kept him awake at night.
He has seven countries to watch over, from Sudan to Somalia. He spends half his time flying round the region meeting presidents and their ministers, coaxing them to get tough on terrorism.
I asked him if this meant the Pentagon was gearing up to go into Yemen and Somalia.
Not necessarily, he replied. The US, he said, would much rather that the host countries pursued al-Qaeda themselves.
But now that the US has special operations troops here on the ground it does have, he said, the ability to react extremely quickly.
And I have seen them myself: silent, lantern-jawed men with tired eyes and deep tans. For months now, they have been kicking their heels here, waiting for a mission.
With al-Qaeda still active in the region, they will almost certainly get one. The only question is who will be the first to strike.