As cruise missiles began raining down on Afghanistan, the world could be in no doubt last night - time has finally run out for the Taliban regime. But what will happen next? NIGEL BURTON reports

A WAR which began amid unimaginable horror almost a month ago has now entered its second phase in a distant land already ruined by a century of continuous conflict.

President George Bush summed it up when he addressed the American people: "The Taliban has had its chance.

"We will win this conflict by a patient accumulation of successes. Every nation has a choice to make. In this conflict there is no neutral ground.

"If any government sponsors the outlaws and killers of innocents, they have become outlaws and murderers themselves and they will take that lonely path at their own peril."

The number one objective for America is to hit back against one man - Osama bin Laden - and his terror organisation, al Qaida, which translates to The Base. In order to achieve this, it has become clear that the Allies must be prepared to remove Afghanistan's ruling Taliban regime from power.

The Taliban - which comes from the Persian word for students - came to power in 1995 after years of chaos following the withdrawal of Russian forces from the country.

Emerging from the Mujahideen guerrillas who fought Soviet troops during the 1979-89 occupation, they swept across the country, ruthlessly imposing strict Islamic sharia law as part of a mission to create a pure Islamic society.

The regime's ruler, Mullah Mohammed Omar, is a one-eyed veteran fighter who is rarely seen in public and is said to have visited the Afghan capital Kabul only twice.

He is said to cut a striking figure, wearing a black shawl which legend has it belonged to Islamic prophet Mohammed.

Omar is rumoured to live as a neighbour of bin Laden in the southern Afghan city of Kandahar, and to have married one of bin Laden's daughters, though the Taliban deny it.

Saudi-born bin Laden has been identified by both the US and Britain as the prime suspect in the terror attacks on New York, Washington and Pennsylvania.

Flushing him out - or killing him - will be no easy task. Bin Laden is unlikely to stay in one place, waiting for US special forces to come calling. He will move around the country, using the mountainous terrain to hide himself and his most loyal lieutenants.

This makes launching missile strikes against the al Qaida chief difficult, particularly after America's failed 1998 attempt to bomb bin Laden which did little more than make holes in the desert.

One option may be to use highly-trained ground troops.

One American general asked for his opinion last night commented: "While this operation is visible, many others are not."

He was referring to special forces - Delta Force, the US Rangers and Britain's own SAS - who will play a crucial part hunting for bin Laden on the ground.

More than 1,000 men have been quietly inserted into Afghanistan since September 11. It is their job to track al Qaida, identify it and help destroy it.

The first battlefield of the 21st Century will be patrolled overhead by unmanned spy planes, or "drones", which relay live video images to analysts hundreds or even thousands of miles away.

The planes, most of them Predators which fly at about 10,000ft at 350mph, operate from bases up to 500 miles away and stay in the air for 24 hours.

Their cameras and sensors can "see" in the dark and peer through cloud cover to reveal what is happening below.

They may be joined by even more advanced spy planes, Global Hawks, which fly unmanned at 65,000ft, far out of the range of anti-aircraft weapons, relaying video and still images from the ground by day or by night.

Also in the air will be the Joint Surveillance Target Attack Radar (Joint STAR), modified Boeing 707s which over-fly battlegrounds, picking out targets and relaying information to ground troops.

The initial phase has been limited to military targets and the Taliban infrastructure.

In Kabul, the defence ministry was attacked; in Kandahar, a command base used by the Taliban army levelled by B52 bombers; and at Jalalabad, Taliban military bases attacked.

The country's airports were cratered to prevent planes landing and taking off.

Attacking these targets will cut Afghanistan's few ties with the outside world (this is a country with only 200 miles of proper roads) and remove its army's high command. With the Taliban relying so heavily on local warlords, who are paid for their allegiance, the Allies must be hoping the regime will collapse from within.

Bin Laden is known to have at least half a dozen training camps around Kabul. He also has suspected bases spread along the Pakistani border and still more near Kandahar, in the south.

The vast array of US weaponry includes so-called "bunker buster" bombs which could penetrate bin Laden's underground lairs and back up President Bush's vow to "smoke the terrorists out of their holes".

Petrol-based "sunshine bombs" might be used to try to wipe out bin Laden's camps in fireballs.

Other options could include an air assault on Kabul using B52s and cruise missiles, or even a ground invasion from Pakistan or Uzbekistan.

America is following the template laid down by the Gulf War: a sustained bombing campaign designed to disrupt communications, demoralise troops and spread panic and confusion, followed by a ground operation.

The Taliban's weaponry is said to include a wide range of Soviet or Chinese-made guns, ranging from 76mm mountain guns to 152mm howitzers, plus a number of lorry-mounted BM21 and BM22 multi-barrelled rocket launchers.

They are believed to have inherited 650 Soviet-made battle tanks from the former Afghan forces.

There are also unconfirmed reports that it has a number of Scud-B surface-to-surface missiles

None of these will prove particularly effective against US weaponry. B52 bombers fly too high to be endangered from anti-aircraft fire and cruise missiles are unmanned.

The danger will come when America commits substantial ground forces because the Afghans are well versed in fighting in the mountainous terrain.

Allied troops will be delivered in Boeing C17 aircraft, which can fly non-stop from the US to tiny grass airstrips in central Asia, where waiting silent helicopters will whisk them to the front line - or, more likely, behind enemy lines.

Once on the ground, soldiers will have helmets which include a video camera relaying pictures to headquarters, an infra-red camera for night vision and a microphone for instant communication. The SAS have already used similar equipment to train for such a conflict.

The most advanced helmets include a display unit, similar to those used in fighter jets, which are linked to the Global Positioning System (GPS) satellites and show where other soldiers and suspected enemies are.

Units are also equipped with battlefield computers, which use the same Windows software and Intel chips as home computers, but which are designed to give information about where other units, suspected targets and different types of terrain can be found.

As they move across the terrain using the system, the electronic soldiers could use a modified version of the standard-issue M4 rifle, which includes a laser for calculating distances and a thermal-imaging system for "seeing" targets through smoke or foliage.

Other soldiers will use double barrelled rifles, known as the Objective Individual Combat Weapon. One barrel fires conventional bullets, while the other launches laser-guided 20mm shells more than half a mile, where they explode in the air above trenches or foxholes, wiping out a dug-in enemy.

Behind the lines, headquarters will be able to call in the latest missile and bombing technology to back up their ground troops.

Modified cruise missiles, deployed last night, use the GPS system to home in on their targets and have far greater accuracy than in the Gulf War.

And bombs have also been equipped with the system, so they, too, can home in on their targets when they are dropped by B52s, the Cold War bomber designed to drop nuclear weapons, and B2 Stealth bombers, which are designed to be invisible from radar.

The war is being fought in Afghanistan, but millions of Americans, and people in Britain, will be holding their breaths to see how - or if - al Qaida can strike back. The Pentagon gave a stark warning last night that further terrorist strikes were "a 100 per cent certainty".

America and her allies have entered a war like no other in history. It is a battle not against a state or even a regime, but against an elusive enemy with terrorist cells in up to 50 countries.

These strikes mark the beginning of a new chapter in the fight against terrorism and no one knows how it will end