Charles Glass: Is anyone surprised by Zawahiri's outburst?

Clinton's assertion of a right to respond to violence with violence expressed the ethos of the vigilante rather than a constitutional government. It was only a matter of time until the other side claimed the same right. On Thursday, four weeks after the suicide bombings in London, Osama bin Laden's Egyptian deputy, Ayman al-Zawahiri, recast on television the Clinton-Bush Doctrine in his terms to the Americans and British: "You, however, shed rivers of blood in our land, so we exploded volcanoes of blood in your land."

Can anyone - apart from Tony Blair who is in permanent denial that the Iraq invasion had any consequences at all - be surprised? Even those of us who detest al-Qa'ida's vision for Islamic tyranny in Muslim lands, and its recourse to violence against innocents, understand this part of Zawahiri's message: "Your salvation will only come in your withdrawal from our land, in stopping the theft of our oil and resources and in ending your support for the corrupt and corrupting [Islamic] leaders." However much one may disagree with Zawahiri's means, one objective - of leaving the Muslim world to govern itself and use its oil wealth as it thinks best - is hardly contentious. It corresponds more closely to the United Nations Charter than do invasions launched under false pretexts and without UN sanction.

Terrorologists are analysing the Zawahiri tape to discern whether he is in operational control of London's bombers. If he is, the Afghan invasion was a waste of time. If not, the bombers don't need al-Qa'ida for anything more than inspiration. What matters most is what attracts so many Muslims - including millions who would not consider using terror against anyone - to al-Qa'ida's goals?

Zawahiri threatened the US: "If you continue the same policy of aggression against Muslims, God willing, you will see the horror that will make you forget what you saw in Vietnam." George Bush and his Defence Secretary, Donald Rumsfeld, responded. Bush made a connection between Islamic terrorism and Iraq: "The Iraqis want to live in a free society. Zawahiri doesn't want them to live in a free society. And that's the clash of ideologies: freedom versus tyranny." Many Iraqis would reply - and many do respond daily with attacks on American and British forces - that foreign occupation does not equal freedom. A precondition of freedom is self-determination, impossible in a country occupied by an army stronger than its own.

Rumsfeld was correct when he said: "There was no war in Iraq or Afghanistan when America was attacked on September 11. And there was no war in Iraq or Afghanistan when terrorists attacked the Beirut barracks in 1983, in the Khobar Towers in 1996 or the African embassies in 1998, or when they attacked the USS Cole in the year 2000." Islamic fundamentalist animosity towards the United States pre-dates the American invasions of Afghanistan and Iraq, but it is a reaction to American policies and actions.

In 1983, a suicide bomber destroyed the US Marine barracks in Beirut; because the Shia Muslim Hizbollah sought to expel Israel and its American backers from Lebanon. Israel had invaded Lebanon with ruthless ferocity in the summer of 1982, killing more than 10,000 people in the process. For an entire summer, it held Muslim west Beirut under siege - sometimes cutting water and electricity. General Ariel Sharon's goal was to expel the Palestine Liberation Organisation from Lebanon and to impose a compliant regime in Beirut. Hizbollah and a majority of other Lebanese rejected Israeli occupation, the massacres of unarmed Palestinians by Israel's Christian allies and American support for an unpopular government. The other examples Rumsfeld disingenuously listed have roots in prior American involvement in the Arab or wider Muslim world. But Britain had suffered no such attacks when it invaded Iraq - the specific motive given to Italian police by the escaped suspect Hussain Osman.

The conflict between the US and the Middle East - over oil and Israeli occupation - is bigger than Iraq. Yet Iraq raised the stakes, because carnage there was bound to inspire violent answers to Anglo-American violence. The peaceful demonstrators who marched all over the world to prevent the Iraq invasion in early 2003 sought to save Iraqi lives as well as their own. Now, both have been lost. Blair and Bush took the risk, and London's commuters paid the price.