If Bush wants an invasion, it could become more costly than Vietnam

President Bush is talking about a "crusade'' ­ it would be difficult to find a word more likely to enrage Muslims ­ but if he plans to wage it in Afghanistan, the United States faces a military campaign more fraught and potentially even more costly than Vietnam.

Ground troops may be necessary to seize Osama bin Laden but they will be entering a country containing one tenth of the world's land mines, left by Soviet occupation forces across 80 per cent of the land.

Besides, anyone who wants to invade Afghanistan needs friends. The Russians had the communist government of Babrak Karmal. But, with the murder of the only serious opponent of the Taliban, Shah Masood, by Arab suicide bombers nine days ago, the United States hasn't a single friend in that cemetery of foreign armies.

So, are the Americans planning a mere attack by cruise missiles? They fired 70 missiles at Osama bin Laden's camps after the bombing of the US embassies in Nairobi and Dar es Salaam ­ they knew where they were, of course, because the camps were built by the CIA during the Afghan-Russian war ­ but they did not touch Mr bin Laden. Do they plan to use special parachute units to descend on the areas around Kandahar where Mr bin Laden has been known to live in the past?

And what about those mines? If the Americans are even contemplating a ground force, it can enter only from Pakistan ­ the most dangerous main supply route it would be possible to find ­ and up the Kabul Gorge from Jalalabad. But the Russians seeded the perimeters of Jalalabad, Kandahar, Khost and Herat with anti-armour mines. There are, in Afghanistan today, more than 10 million mines. They lie in fields, on mountainsides, beside roads, around the big cities, along irrigation ditches. On average, between 20 and 25 Afghan men, women and children are blown up by mines every day ­ even if we take the lower figure, this indicates 73,000 civilian casualties from these mines in the past 10 years alone.

A military incursion would, therefore, need an army of mine clearance specialists as well as soldiers, men who would have to inch their way over the roughest terrain in the world ­ while under attack ­ to make the roads and countryside safe for the Americans and their allies. Of Afghanistan's 29 provinces, 27 are littered with mines.

During their savage 10-year occupation, the Russians also planted thousands of mines in "security zones'' around Afghanistan's airports, power stations and government installations. Western non-governmental organisations working in the country two years ago estimated that it would cost £80 per mine to clear Afghanistan's 10 million mines ­ and 45 days to clear merely a square mile of land. There are now two million disabled men, women and children in Afghanistan. No infantry can march across this territory.

And then there is that main supply route. Pakistan has already made clear that it will not involve its own military in a campaign, although there are suspicions that enough money might persuade General Musharraf ­ now respectfully referred to as President by the Americans even though he took the presidency illegally ­ to change his mind. However, the "Jihadi" culture has already impregnated the Pakistan army and there is a real possibility of unrest turning to civil war if the Americans arrived to invade Muslim Afghanistan.

The very border areas through which a Western army would have to pass are held by men loyal to the Taliban. On the Pakistani side of the frontier, there are now 2,000 Taliban madrassas (schools) where religious teaching is given not only to potential mujahedin but to Chechen and Tadjik fighters as well.

The policemen who guard these madrassas constitute a mere facade of governmental control.

Even if the Americans penetrated Afghanistan, their shells would only plough over the ruins. The Russians tried to destroy the Taliban's predecessors with 10 years of bombing, destroying whole villages, with their people, farm animals, fields, trees and mud huts. And still they could not get rid of the mujahedin, still they could not ­ to use Mr Bush's inappropriately folksy phrase ­ "smoke them out of their holes''.

With Pakistan as its only, broken ally among Afghan-istan's neighbours, with no friends inside the country and 10 million hidden land mines lying across its mountains and fields and cities, Mr Bush's "crusade'' looks more than dangerous. We are now being told that the United States is no longer afraid to take casualties. America, the President says, will have to accept losses. He'd better be right.