But if the Bin Laden construction company made his family into millionaires, its convoys of earth-moving trucks, bulldozers and quarrying equipment took him to war. The Afghan conflict against the Russians moulded Bin Laden, taught him the meaning of his religion, made him think. Anyone who wants to understand the man whom Bill Clinton has dubbed "America's Public Enemy Number One" should study this moment in his life. The West regarded him as a hero. In those days the young Arabs whom he brought to Afghanistan to fight the Soviet occupation army - around 9,000 at a conservative estimate - were treated as heroes; the Times used to call them "freedom-fighters". Few noticed - or bothered to study - the theological implications of the West's support for the mujahedin.
One of the reasons Leonid Brezhnev was persuaded to send his troops into Afghanistan was the reports that large areas of the countryside had fallen under the sway of Muslim fundamentalists. Government schoolteachers, installed by the Communist regime in Kabul, were being assassinated. Even when the mujahedin were shooting at civil airliners with British-made Blowpipe missiles, they were not called "terrorists".
Bin Laden saw his comrades die in their hundreds, while he, miraculously, survived Russian kidnap attempts - the Soviets understood Bin Laden's importance even then - and mortar fire. With the road-building equipment he had brought across the border from Pakistan, he carved a highway through the mountains to within 15 miles of Soviet-occupied Kabul. In the later stages of the war he drove captured Russian tanks up this same road. Into the sheer face of a mountain, he built a 25ft-high air-raid shelter, reached by perilous stone trails hacked into the rock. "What I lived in two years there," he was to recall later, "I could not have lived in a hundred years elsewhere."
Bin Laden was sickened by the factional fighting among the Afghans that followed the departure of the Russians - it was a period of bitter disillusionment for the Saudi - and he moved to Sudan, using his personal wealth to finance road construction projects in the desert north of Khartoum. It was while he was here, in the years that followed the Afghan war, that reports came from Egypt and Algeria of Arabs returning home in Afghan clothes, many of them deeply religious, contemptuous of the corruption of secular governments, doctrinal to the point of self-righteousness. When I first met Bin Laden in 1993, he was building a highway to connect the remote village of Almatig to Khartoum for the first time in its history, shaking hands with the grateful villagers, worshiped by the local sheikh. "We have been waiting for this road through all the revolutions in Sudan," he said. "We waited until we had given up on everybody - and then Osama bin Laden came along."
Narrow-faced with a long pepper-and-salt beard and sharp, penetrating eyes, Bin Laden shook hands with each man, watched by the young Arab fighters (without weapons on this occasion) and clearly enjoying the adoration. There is something of the evangelist about Bin Laden; not the friendly apostle but the fire-breathing preacher, a hermit of such conviction that argument is out of the question. For the Americans, his epic certainties constitute his greatest danger. Bin Laden is not a man who does deals.
He embarked on another construction; a new motorway that would cut the distance between Khartoum and Port Sudan by 300 miles. By now, Egyptian newspapers were claiming that Bin Laden was helping to organise an Islamist resistance to President Hosni Mubarak's rule from "training camps" in Sudan. "The rubbish of the media and the embassies," Bin Laden retorted. He kept a home in Khartoum, only a small apartment in his native Jeddah. His four wives lived with him in Sudan. Three of them were later to follow him back to Afghanistan, along with his two sons; for months they lived in three small tents beside a row of trees east of Jalalabad.
He had watched his beloved Afghanistan torn apart by greedy men who had forgotten their religion. Now he saw corruption in Egypt, in all the Arab nations that had adopted a facade of Western life; above all, in Saudi Arabia. For Bin Laden, the betrayal of the Saudi people began 24 years before his birth, when Abdul Aziz al-Saud proclaimed his kingdom in 1932. "The regime started under the flag of applying Islamic law and under this banner all the people of Saudi Arabia came to help the Saudi family take power," he was to tell me later in Afghanistan. "Abdul Aziz did not apply Islamic law; the country was set up for his family...
"When the American troops entered Saudi Arabia [after Iraq's invasion of Kuwait], the land of the two holy places [Mecca and Medina], there was a strong protest from the ulema [religious authorities] and from students of the sharia law all over the country against the interference of American troops. This big mistake by the Saudi regime of inviting the American troops revealed their deception. They had given their support to nations that were fighting against Muslims. They [the Saudis] helped Yemen Communists against the southern Yemeni Muslims and helped [Yasser] Arafat's regime fight against Hamas. After it insulted and jailed the ulema [for objecting to the American presence] ... the Saudi regime lost its legitimacy."
Under pressure from the Americans, the Sudanese told Bin Laden to leave and Bin Laden returned to the land where he had been a hero. Some say he travelled back to Afghanistan via Saudi Arabia; certainly, he has many sympathisers there, including some members of the royal family as well as preachers. Which is why he maintains contact with his country through the Saudi embassy in Islamabad. Saudi Arabia's Taliban army protects him; he has expressed his admiration for the "stability" they have brought to Afghanistan - his own strict interpretation of Islamic law fits in rather well with the Tali-ban's ferocious regime of punishment and anti-feminism. In those initial months back in Afghanistan, he must have decided that if he could defeat the Russians, he could also defeat America.
Saudi Arabia, he concluded, had become "an American colony". Ordinary Saudis realised the imprisoned ulemas were right: US troops had stayed on in the kingdom, despite their promise to leave. "What happened in Riyadh and Khobar [when 24 Americans were killed in two bombings] is clear evidence of the huge anger of the Saudi people against America," he told me in 1996 as we sat in an Afghan camp surrounded by his armed Arab followers. "The Saudis now know their real enemy is America." No, he said, he didn't organise those bombings. But he knew two of the three men beheaded by the Saudis afterwards. (The Americans suspect they were innocent, executed to cover up for important Saudi officials.)
Did not the Europeans resist German occupation in the Second World War, Bin Laden suddenly asked. I told him this parallel was morally wrong, that no European would accept the argument because the Nazis killed millions of Europeans; the Americans had never murdered a single Saudi. His reply was the same as it might have been this weekend, in the aftermath of the American missile strikes. "We as Muslims have a strong feeling that binds us together ... We feel for our brothers in Palestine and Lebanon. The explosion at Khobar [in Saudi Arabia] did not come as a direct result of American occupation, but as a result of American behaviour against Muslims ... When 60 Jews are killed inside Palestine, all the world gathers within seven days to criticise this action, while the deaths of 600,000 Iraqi children (because of UN sanctions) did not receive the same reaction. Killing those Iraqi children is a crusade against Islam ... I believe that sooner or later the Americans will leave Saudi Arabia and that the war declared by America against the Saudi people means war against all Muslims everywhere. Resistance against America will spread in many, many places in Muslim countries. Our trusted leaders, the ulema have given us a fatwa that we must drive out the Americans."
Guilty or not of the embassy bombings in Africa - and America still has to tell us about its "compelling evidence" - President Clinton has taken on a very dangerous enemy.