President Bush and his military advisers were considering their options yesterday for retaliation over last week's attacks amid a growing realisation in Washington that America's "new war" will be like no other it has fought.
In the Indian Ocean and the Gulf, heavily armed US battle groups, complete with attack bombers, are at a state of alert while special forces are also being mobilised in preparation for a possible deployment of ground forces in Afghanistan.
As George Bush visited the Pentagon, where he again met his military advisers, he once more vowed that he would not allow "terrorists to intimidate America". Donald Rumsfeld, his Defense Secretary, said the fight against such terrorists would require the use of unconventional military methods. America's extensive and heavily equipped military machine has a number of options. But most experts believe the response will be two-pronged, involving a swift, initial military attack using bombs or cruise missiles and possibly élite troops, followed by a sustained economic, military and diplomatic campaign.
What is becoming clear is that Mr Bush's administration accepts that any effective attack against Osama bin Laden will not be possible using only guided bombs, launched from warplanes flying at relative safety of an altitude of 15,000ft or more, as was the case in the Kosovo conflict. There is also the recognition for the first time since the Somalia débâcle almost a decade ago that American casualties are almost certainly inevitable.
Mr Rumsfeld said: "Cruise missiles do not get people who are operating in the shadows. And the era of antiseptic warfare – planes dropping bombs from 20,000ft, cruise missiles flying off in the night, no one getting hurt in the United States or the coalition side – that will not work with this enemy, let there be no doubt."
In addition to air strikes against the 100 or more bases in Afghanistan – including 20 training camps – believed to be linked to terrorism, America's options include the use of élite troops to locate and assassinate Mr bin Laden.
Also on the cards could be the establishment of a more conventional army for a full-scale invasion, as well as boosting support for the Afghan anti-Taliban forces, whose leader, Ahmed Shah Masood, was assassinated this month. Neither America nor the Nato secretary general, Lord Robertson of Port Ellen, has ruled out the use of a battlefield nuclear weapon, while insisting this would be a last resort. Lord Robertson described last week's attack as the equivalent of a guerrilla nuclear attack.
Whatever options are chosen, America's military response will be co-ordinated by the US central command (CENTCOM) based in Tampa, Florida, which oversees operations in the Middle East, South and Central Asia. It is likely that the initial response will involve the battle group based on the Nimitz-class aircraft carrier USS Carl Vinson, which has just arrived in the Gulf and which comprises 70 aircraft – including a squadron of F–14 Tomcat fighters, and three squadrons of F–18 all-weather attack aircraft – a submarine, two cruisers and two destroyers with a combined arsenal of about 400 conventional Tomahawk land attack missiles. In support in the Indian Ocean is the Enterprise battle group, with four squadrons of fighters on the USS Enterprise and 500 Tomahawk missiles on the group's 14 other ships.
Also essential to the American reponse is the role of Pakistan. Alongside Iran, this is the only country that can provide naval-based aviation with access to Afghanistan. One of them must open up their airspace for American aircraft not only transiting the countries, but also carrying out mid-air refuelling.
Stratfor, a military and intelligence group based in Texas and Washington, said: "Whether the attacks come from carrier-based aircraft or long-range bombers from the US or other bases around the world, they cannot reach Afghanistan without passing through one of these countries."
Washington now sees Pakistan as the key to striking at Mr bin Laden and his backers – both geographically and for the intelligence on the Saudi-born dissident that can be provided by Pakistani intelligence.
Uzbekistan, which has an 80- mile border with Afghanistan, may play a role and its government has said it is open to allowing US forces to use Uzbek airspace or its territory for an attack. Tajikistan, another former Soviet republic, has said it will not assist the US.
If President Bush decides to use troops to strike at Mr bin Laden's bases inside Afghanistan, the Commander-in-Chief will have at his disposal a range of élite forces. These include the top-secret Delta Force, Navy SEALs and the 75th Ranger Regiment or the 82nd Airborne. There were reports yesterday – officially denied – that the Rangers had been given battle orders.
Experts have pointed out the problem of tracing Mr bin Laden in a country notoriously difficult for generals in command of conventional armies and a "fantasy for guerrilla commanders". They point out how Afghan fighters – a fast-moving, mobile force – stunned the world when they forced the withdrawal of the invading Soviet Union 12 years ago. One retired commander warned against "embarking on an endless war of attrition against a faceless enemy – think of a global Viet Cong".
As a result of this, experts believe any operation may have to attack a number of sites simultaneously. Retired Air Force General Charles Horner, air commander during the 1991 Gulf war, said he envisaged special forces deploying in teams of between five and 500, entering Afghanistan in helicopters flying over Russian, Pakistan or Iranian airspace.
These units, he said, would have to be supported by heavy air support, from B–2 stealth bombers or even B–52s. The Air Force F–15 and F–16 fighters and the Navy's F–18 fighters would provide additional cover.
The second phase of the two-pronged assault could involve a longer-term operation that would demand diplomatic, economic and military efforts. Michèle Flournoy, a senior fellow for the Washington-based think-tank, the Centre for Strategic and International Studies (CSIS), said: "The most visual piece [of the response] will be a military strike. This may be important for political reasons. But long-term, the non-military responses will be more important." Ms Flournoy said this included the building of an international coalition against terrorism, an effort to cut off funding for such groups and diplomatic effort to ensure states did not harbour terrorists. In addition to Pakistan, the most pressing diplomatic efforts needed to focus on Saudi Arabia, Iran and Syria.Reuse content