In graffiti and on the lips of angry young bearded men, you read and hear one slogan across the Arab and Muslim world. From the Maghreb to the Levant, from the Gulf to Afghanistan, "Islam, houwa al hal" ("Islam is the solution") has been the rallying cry for a generation.

Since 1979 Islamists have taken power in Iran, Sudan and Afghanistan. In the past six years they have fought a savage civil war that has killed more than 100,000 people in Algeria. The West had all but forgotten the low-level insurrection that simmered in Egypt until the Gama'a Islamiya (Islamic group) massacred 67 people at Luxor last Monday.

In Pakistan, where the government pays lip-service to Islamic precepts, rebels nonetheless continue to attack "infidels"; three Americans and their driver were gunned down in Islamabad this month.

Morocco and Jordan have - at least for the time being - managed to accommodate "moderate" fundamentalists by including them in their parliaments. Elsewhere, as in Tunisia, the peace is kept only by a brutal police state which uses torture and mass imprisonment to impose secularism. Only one country, Syria, has annihilated its Islamic opposition, through the brutal slaughter of up to 20,000 Muslim radicals at Hama in 1982.

From the Atlantic Ocean to the Indian subcontinent, Islam has become the main channel of political frustration and violence. Since the second World War, the leaders of these countries have dabbled in all the "isms" - communism, Ba'athism, socialism, Nasserism, capitalism - and all failed to provide a modicum of political participation, economic well-being or social justice for their populations.

The poverty of Egypt has to be seen to be believed. In the Nile Delta villages where they live in mud huts alongside open sewers, families sell their daughters to visiting Gulf Arabs for summer-long "pleasure marriages". Children as young as four work 10-hour days, making fake Persian carpets in sweatshops.

At the same time, Egyptians see the glittering hotels where tourists stay. They know the sons of government ministers reap millions from weapons contracts, drive the newest Mercedes and BMWs and live in palaces. The hatred of the poor for the privileged few is visceral.

The same holds true of Algeria. In the slums of Algiers I have seen crumbling apartment blocks where 25 people sleep in shifts in two small rooms. Yet satellite TV dishes provide them with a constant picture of the affluence of the West, which their own leaders share. Because all avenues of democratic protest are cut off, and because their societies provide no hope of a better life, young men turn to Islamic groups.

In an editorial about the Luxor massacre, the Washington Post said it was "obscene to ponder an `explanation' of what occurred". I thought of Ramadan, a young Algerian slum-dweller I interviewed early in the Algerian war. "The government are vermin, snakes," he said. "I will fight beside anyone who is against them."

When you compound such feelings with the wide-scale arbitrary arrest and torture, summary executions and dynamiting of houses that have occurred in Egypt and Algeria, it is not surprising that armed Islamic groups find no shortage of recruits. In Egyptian prisons men are given female names and forced by guards to sodomise one another.

By supporting the regimes in power, the West has become linked in the minds of Muslims with their cruel rulers. Foreigners who travel to these countries are considered legitimate targets by the militants. Their assassination is the most effective way of sabotaging the tourism and trade that finance the regimes in power.

In Algeria 108 foreigners have been murdered since 1993. Egypt is fast catching up; the atrocity at Luxor brought the total there to 98 foreigners killed in the past five years.

Just as Europeans are often ignorant of the huge cultural differences between Arabs and Muslims, many Arabs see the West as a Christian, "infidel" monolith, with the US as leader. The US is inseparable from its Israeli client state, and the dispossession of millions of Palestinians. These are the "explanations" which the Washington Post calls "obscene".

While the West is horrified by the killing of more than 200 foreigners in Algeria and Egypt, the Arabs recall the deaths of 17,000 people in Israel's 1982 invasion of Lebanon and more than a million children who have died because of UN sanctions against Iraq, according to UN estimates.

Arabs feel threatened by Israeli nuclear weapons, and they point out that Israel has never been forced to comply with a single UN resolution. Only an infinitesimal minority of Muslims approve of the atrocity at Luxor, but when they consider their own lives, Arabs say the balance of terror lies with the West, not Islam.