The cracks began to appear in the early days of Brown’s term, when two members of his government suggested the London-Washington bond would not be quite as tight as it had been under Blair. The fissures opened further on July 30 when the new prime minister had his first official meeting with Bush and—straying from his prepared text, NEWSWEEK has now learned—described their discussions as “full and frank,” diplomatic code for disagreement.

Since then, the sniping has intensified. In Afghanistan, a British commander told The New York Times that U.S. airstrikes resulting in civilian casualties were “counterproductive” in the battle for Afghan hearts and minds. Foreign Secretary David Miliband, in an Aug. 7 letter to U.S. Secretary of State Condoleezza Rice, seemed to ratchet up the British government’s criticism of post-9/11 U.S. detention practices, calling for the release of five British residents imprisoned at Guantánamo Bay, Cuba. Meanwhile, in Washington—where the State Department is no longer simply dismissing British censure as the work of off-message officials—the Bush administration is fretting over growing signs that the Brits might withdraw their troops from southern Iraq ahead of the president’s preferred schedule.

The growing distance should not, however, be overblown. For one thing, the partnership has survived rough patches in the past, such as Prime Minister Harold Wilson’s refusal to commit British troops to the American war effort in Vietnam and President Ronald Reagan’s hesitation in backing Britain against Argentina in the Falklands War. For another, the Blair-Bush bond forged in 9/11, like the Churchill-Roosevelt dynamic in World War II, was an exceptional moment in the history of the special relationship in which both men saw themselves as battlers on the side of good versus evil.

A pragmatist, Brown was never going to buy into the neoconservative American agenda in the way Blair did. As he tries to move out of Blair’s shadow—and to recover the popular support Blair lost by so fervently backing Bush—Brown is recalibrating the special relationship, not threatening it. A keen student of American history, he views the transatlantic alliance through a longer lens than Blair. He’s made this point on several occasions since he took office, tracing the arc of this relationship from the Magna Carta to the Declaration of Independence (where Britain’s idea of liberty “found its most famous expression”) and from World War II to today.

Even as his subalterns have criticized U.S. foreign policy—saying London and Washington should not be “joined at the hip,” and calling for a “multilateralist, not unilateralist” approach to global crises—Brown has stepped in to soothe American concerns. He has ordered his chief of staff to write a letter to all cabinet ministers reaffirming that the U.S. tie “is our single most important bilateral relationship.”

No one doubts that, even now. But the war in Iraq and its aftermath, which among Britons are the sources of the fiercest criticism of the United States, have fundamentally changed this partnership. Even the Conservative Party, ordinarily a more reliably hawkish supporter of Washington’s military adventures than Brown’s Labour Party, has taken to warning against a “slavish” relationship with the United States. For the foreseeable future it will be difficult, if not impossible, for any British government to follow America into war again. One hopes it won’t take a test of that magnitude to prove just how special the relationship is in the Brown-Bush era.