This week's barbaric terrorist attacks in London, which claimed dozens of lives and injured hundreds of people, were a direct assault on the Anglo-US alliance, the engine of the global war on terror. An al Qaeda splinter group calling itself "the Secret Group of al-Qaeda's Jihad in Europe" claimed responsibility for the multiple blasts. The motives behind the Al Qaeda attack - if it does indeed turn out to be them - are clear. With Britain universally acknowledged as America's closest ally, an attack on London is no different than an attack on Washington or New York.

By striking London, the world's biggest international financial centre, al Qaeda hoped to achieve a three-pronged propaganda success. First, it planned to decisively disrupt the meeting of the Group of 8 (G8), a symbol of the most powerful western leaders in the world. As is already clear, that aim has failed, as the G8 reached agreement on substantially increasing aid to Africa and several other matters. Second, it hoped for the "Spanish effect", to alienate the British public from its government, as was so successful in Madrid. Here, too, the terrorists are bound to fail, for they have underestimated the strength and resolve and very different political culture of the British people.

A third goal of the attack was to fracture the common Anglo-American partnership in Iraq by making the price of co-operation with the United States too costly to bear. Last Thursday's cowardly bombings in London are closely modelled on the Madrid attacks of March 2004 and are especially aimed at forcing a British withdrawal of its 8,000 troops from Iraq.

It is here yet again that the Anglo-American alliance stands as the bulwark of western civilisation. Almost all foreign policy experts agree that an immediate withdrawal from Iraq would be a cataclysmic defeat for the West and an immense victory for Abu Musab Al-Zarqawi and his murderous cohorts. But it will not come to that the ties that bind the United States and the UK are too strong, and too much is at stake.

The terrorists fail to understand the British bulldog tradition of rising to meet a crisis. They also fail to comprehend that when the chips are down the United States and UK, like Butch Cassidy and the Sundance Kid, may bicker, fight, and squabble, but we always come out shooting together. This terrible atrocity will not alter these fundamental facts; rather, it will only strengthen the Anglo-American resolve. Britain, like America, is a great nation that will always respond aggressively to primary threats to its national security, such as this callous murder of its citizens.

The terrorists responsible for this outrage will not succeed in changing British policy in Iraq and in the war on terrorism. If anything, given the reality of British political culture, the attacks will increase the determination of the British government to stay in Iraq and may actually result in an expansion of British troop levels in the country.

Prime Minister Tony Blair is no Jose Luis Rodriguez Zapatero, the socialist politician who took over from Jose Maria Aznar last year. The decision by the Zapatero regime to withdraw Spanish forces from Iraq in the wake of the Madrid bombings was an appalling capitulation to terrorism, and sent the wrong message to al-Qaeda - that the West is weak, and that it will surrender under pressure. Spain's appeasement of the terrorists emboldened those intent on the destruction of the transatlantic alliance. Blair, as well as ordinary Britons, is well aware of this. Al-Qaeda's basic mistake is in assuming that all Europeans (and the British) are likely to act as the Spanish have their lack of understanding that Europe is a very diverse set of very different cultures and peoples is understandable given recent tendencies to falsely see the continent as a monolithic. Understandable, but as French President Jacques Chirac recently found out, absolutely wrong. Britain is simply not Spain.

In the coming days Zapatero and his allies Jacques Chirac and German Chancellor Gerhard Schroder will no doubt be urging restraint on the British government, and counselling against the use of military force. The European Union's (EU) response will be to treat the London bomb attacks as a law and order matter, not as an act of war.

Blair should resist the lacklustre approach of his European colleagues, and treat the bombings for what they are, an integral part of al-Qaeda's war to destroy the West. The European Union (EU) is sleepwalking to disaster with its blase approach to fighting international terrorists. No European country is immune to the threat of terrorist attack, and without doubt al-Qaeda cells are already planning further attacks on European soil.

Make no mistake, this is an epic confrontation between civilisation and the barbaric forces that wish its destruction. The common Anglo-American operational response to the bombing must be robust. There has to be immediate retaliation by the United States. and UK the war must be taken to the terrorists. Whoever has harboured, funded, aided, or abetted these terrorists, be they domestic or foreign, must be held to account. If any state has played a role in these attacks, there must be consequences. All options should be on the table.

In addition, a meticulous hunt for the al-Qaeda sleeper cells operating in London and other major cities across Europe must be initiated. No quarter should be given to those who have murdered innocent civilians. There also has to be a reversal of the crippling defence cuts of the last few years, which have seriously hampered Britain's ability to deploy large numbers of troops at short notice to battlefields across the globe. A doubling of the size of the Special Air Service should also be implemented. In an increasingly dangerous world, Britain must bear a greater load of the burden carried by the United States in the war on terror. As this past week's events have shown, this is as much Britain's war as it is America's.

At Britain's hour of need, the United States will stand shoulder to shoulder with her British allies, who are bloodied but unbowed. This latest terrorist attack will only succeed in bringing the British and American people closer together. The terrorists' fatal conceit is similar to that of the Kaiser, Hitler, and Stalin: underestimating the power and determination of the Anglo-Saxon peoples.

The US-British alliance is a strikingly successful partnership of two great powers built on the solid foundations of a common heritage, culture and vision. The two nations have fought alongside each other in seven major wars in the past 90 years, from the first world war to the second Gulf war. The war on terror is a global conflict that may last for decades but will ultimately be won by the two nations that stand at the forefront of defending freedom and liberty on the world stage.

Nile Gardiner, Ph.D., is a fellow in Anglo-American security policy at The Heritage Foundation.

John Hulsman is research fellow in European affairs at the Heritage Foundation.