What is really irking the radical Islamists?

This theory is superficially plausible, but it fundamentally misunderstands both the causes of the anger and despair that lead Middle Eastern people to perpetrate or support terrorism, and the extent to which Western policies can affect public opinion in the non-democratic nations of the region.

Muslim terrorists and their supporters do point to a variety of complaints that, they argue, prove Western enmity. But if we look at some of the issues they raise, such as the loss of Spain in 1492 and the Crusades - as well as the widespread claim that the September 11 attacks were actually a US or Israeli conspiracy - it becomes clear these grievances are just the expression of a deeper crisis of identity and confidence.

As renowned Middle East historian Bernard Lewis has explained, Muslim civilisation is aggrieved and confused because of an unexpected reversal of fortune over the past 200 years. It has gone from leading the despised Christian West in the sciences, economic wellbeing and military power to falling far behind. This contradicts and calls into question the Muslim understanding of their own history and religion. The resulting trauma led to an ongoing struggle among Muslims to explain, as Lewis termed a recent book, What went wrong?

Essentially, the Middle East has become dominated by a totalitarian model that destroyed traditional freedoms and stifled economic growth, while educating generations of Arabs to oppose commerce, pragmatic compromise and Western science.

Al-Qaeda terrorists are Islamists - totalitarian ideologues who argue that a return to the supposedly pure Islam of the prophet Mohammed's times, under a universal Muslim ruler or Caliph, will fix all Middle Eastern problems. Their world view impels them to see Islam and non-Islamic societies as eternally at war.

Meanwhile, those who argue that the London attacks were a response to the war in Iraq should note that both September 11 and the Bali attacks preceded the war. It cannot be plausibly argued that al-Qaeda would have voluntarily stopped doing what it was already doing - planning large-scale murderous attacks on Western civilian targets like London - if the Iraq war had not gone ahead.

Of course, a resolution to the Arab-Israel conflict is extremely desirable. But those who argue that it would solve the problem of Islamist terror need to be reminded that the September 11 attacks were planned during the Clinton administration, when the US was making an unprecedented effort to find such a resolution. Even if a viable two-state solution were found tomorrow, it is unlikely to satisfy the current Muslim and Arab sense of grievance over the issue. The Arab Middle East has been taught for too long that Israel's existence is an intolerable affront and threat. Any realistic peace deal will be attacked by radical groups for decades to come.

Finally, actual policies have very little effect in the non-democratic societies of the Middle East, where almost all information is controlled by either the state or radical opposition groups. Middle East regimes are masters at distorting outside policies and initiatives to serve their interests. Maintaining a sense of grievance against outside parties helps keep them in power. Therefore, it is almost impossible to conceive of any change of Western policy that would, in itself, significantly lessen the widespread sense of grievance in the Middle East.

Only democratisation can do this. Democracy opens up information sources, provides other outlets for dissent and anger, promotes economic growth and encourages a culture of compromise and pragmatism. Studies also show that terrorism is strongly correlated with a lack of political freedom (but has almost no relationship with poverty).

The key to democracy is dealing with the entrenched autocratic order in the Middle East. All signs are that the removal of Saddam Hussein has uncorked a wave of interest in democracy across the region. Now we must ensure the Iraqi experiment succeeds - in the face of terrorist opposition from international Islamists, aided by the regimes of Syria and Iran, who oppose democracy in Iraq because it threatens them.

This is the only practical way to marginalise the radical Islamist ideology that is the real root cause of terrorism.

Dr Colin Rubenstein is executive director of the Australia-Israel & Jewish Affairs Council.