Today's barbaric terrorist attacks in London, which claimed at least 37 lives, are a direct assault on the Anglo-U.S. 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" has already claimed responsibility for the multiple blasts. The motives of this organization 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, al Qaeda hoped to achieve a three-pronged propaganda success. First, it planned to disrupt the Group of 8 (G-8) meeting, a symbol of the most powerful Western leaders in the world. As is already clear, that aim has failed. Second, it hopes 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 of the British people.

A third goal of the attack is to fracture the common Anglo-American partnership in Iraq by making the price of cooperation with the United States too costly to bear. Today's cowardly bombings are closely modeled 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 civilization. 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 U.S. and the UK are too strong.

The terrorists fail to understand the British bulldog tradition of rising to meet every challenge. They also fail to comprehend that when the chips are down the U.S. and UK, like Butch Cassidy and the Sundance Kid, come out shooting together. This terrible atrocity will not alter these fundamental facts; rather, it will only strengthen the Anglo-American resolve.

The terrorists responsible for this outrage will not succeed in changing British policy in Iraq and in the war on terrorism. If anything, the attacks will increase the determination of the British government to stay in Iraq and likely result in an expansion of British troop levels in the country. Prime Minister Tony Blair is no Jose Luis Rodriguez Zapatero.

Britain is at War

The common Anglo-American operational response to the bombing is obvious. There must be immediate retaliation by the U.S. and UK-the war must be taken to the terrorists. Whoever has harbored, funded, aided, or abetted these terrorists must be held to account. If any state has played a role in these attacks, there must be consequences. Special forces operations, strategic air strikes, and the targeted elimination of terrorist leaders must all be on the table, in addition to a meticulous hunt for the al Qaeda sleeper cells operating in London and other major cities across Europe. No quarter should be given to those who have murdered innocent civilians. Make no mistake, this is an epic war between civilization and the barbaric forces that wish its destruction.

At Britain's hour of need, the United States will stand shoulder to shoulder with her British allies, who are bloodied but unbowed. The terrorists' fatal conceit is similar to that of the Kaiser, Hitler, and Stalin: underestimating the power and determination of the Anglo-Saxon peoples. This is a war 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 Fellow in Anglo-American Security Policy, and John Hulsman Ph.D. is Research Fellow in European Affairs in the Douglas and Sarah Allison Center for Foreign Policy of the Shelby and Kathryn Cullom Davis Institute for International Studies at The Heritage Foundation.