But what happened when a modern Suez, in the form of the invasion of Iraq, came along in 2003? Where was a sober Britain to rein in President George W. Bush? Nowhere. Indeed, Prime Minister Tony Blair cheered Bush on in a cause they embraced with equal fervor. Suez marked a turning point in British history: the foreign-policy establishment vowed never again to be on the opposite side of the United States in an overseas crisis. But Iraq is turning Suez dogma on its head. Whitehall’s new doctrine: better to be out of step with the Americans than to follow blindly.

This is a historic shift. Blair remains unswervingly “shoulder to shoulder” with Bush. But in the depth and fervor of his allegiance to U.S. foreign policy, the prime minister stands virtually alone. Once Blair stands down next year, the two British political leaders likely to set the tone of future U.S.-U.K. relations have both adopted subtly cooler views toward Bush in particular and U.S. foreign policy in general.

Tory opposition leader David Cameron took none other than the occasion of the fifth anniversary of the September 11 attacks to warn against a “slavish” relationship with America. As for his rival for Downing Street, Chancellor of the Exchequer Gordon Brown? Foreign-policy commentator Mark Leonard, writing recently in the Spectator after interviewing key advisers, suggests that as prime minister Brown would “break with Blair’s adventurism” and adopt a “more hard-headed brand of Atlanticism … reserving the right to be critical of American policy in public.”

Clearly, both men are taking their cue from the British public. According to a poll in the Guardian newspaper last week, 69 percent of Britons believe U.S. policy has made the world less safe since 2001, 71 percent believe the war in Iraq was unjustified and 75 percent believe Bush is a danger to world peace, more so than North Korea’s Kim Jong Il or Iran’s Mahmoud Ahmadinejad.

Crucially, the British public does not focus all of its dissatisfaction on Bush personally, as once seemed to be the case. Strong sentiment against the U.S. government, if not outright anti-Americanism, is now entrenched in British popular culture, from pop music and the theater to comedy and prime-time TV. Last week the BBC premiered “The State Within,” a “24”-style conspiracy thriller set in Washington. In it, as relations between the two countries disintegrate, right-thinking British diplomats try to rein in heavy-handed U.S. anti-terror policies, like rounding up all British Muslims in the state of Virginia.

Britons once mourned Suez as the final milestone on the road to imperial decline. Last week, as historians and politicians sifted through the debris of Suez once again, they saw the end of something else: unconditional British support for America. Yes, the “special relationship” is built of strands that run through it like thick steel cables: history, language, culture, economic ties, longstanding military and intelligence connections, and any number of strategic interests. But after Iraq, it will never be the same.