Gordon Brown yesterday surprised commentators by refusing to rule out military action against Iran. “I firmly believe that the sanctions policy that we are pursuing will work, but I’m not one who’s going forward to say that we rule out any particular form of action,” the new British Prime Minister told a news conference. While Brown had previously seemed to follow his European partners France and Germany by playing down the idea of using force against Tehran, his line on Iran yesterday was compatible with the more hawkish position of President Bush.

What are we to make of these maneuvers? Brown’s remarks come just a few days before he is due to make his first visit to Washington since taking over from Tony Blair earlier this month. He can expect a polite but cool reception from Bush. The appointment of former United Nations deputy secretary general Mark Malloch Brown as Foreign Office minister for Africa, Asia and the UN has predictably exasperated the Bush administration.

Former U.S. Ambassador to the UN John Bolton told the Sunday Times of London: “If Gordon Brown knew what he was doing when he appointed Mark Malloch Brown, it was a major signal that he wants a different relationship with the United States. If he didn’t know what he was doing, that is not a good sign either.”

By diverging from the European position on Iran and tacking closer to the American one, Gordon Brown is attempting to limit the damage done by the (soon-to-be-ennobled) Malloch Brown. In a recent interview, the latter’s elevation from bureaucrat to baron seemed to have gone to his head. He claimed that a “radical” change in British policy towards the U.S. was in the offing, with the two leaders no longer “joined at the hip”. He also boasted of his status as a “wise eminence” and his contacts in America. It was so embarrassing that his boss, Foreign Secretary David Miliband, was forced to go on TV himself to contradict his subordinate.

Gordon Brown has proved to be more nimble on his feet than his critics expected, and he is quite capable of creating some good publicity for himself in advance of his trip to confound the expectation that Mr. Blair, the darling of Washington, is an impossible act to follow. Iran, though, is too important to be treated as a pawn in a transatlantic diplomatic game. The decision that the President makes on this—whether to pre-empt Ahmadinejad’s armageddon—could be the most momentous of his presidency. Whatever he does, Bush needs to know that he can rely on Mr. Brown when the going gets tough.

By trying to impress both the President and his own largely anti-American party, Brown is trying to be too clever. Sooner or later, he will have to choose. Iran is actually destabilizing the entire region and potentially mobilizing the entire Muslim world against the West. Other European states may choose to turn a blind eye to the danger posed by Tehran’s nuclear program, but the British have had recent and painful experience of the regime’s hostility. Brown needs to erase the memory of the naval hostage crisis as soon as possible. He may not want to be the heir to Tony Blair’s role in the Iraq war, but the logic of the situation with Iran points to the same decision: to do nothing is the worst policy.

If Brown is wise, he will fire his grey eminence before he sets foot in the White House and instead echo one of the greatest of his predecessors, William Pitt the Elder: “Our watchword is security.” The most damaging impression about the liberation of Iraq is that it has made the West in general, and Britain in particular, less secure. If Bush can make a good case that destroying Iran’s nuclear facilities would make not only Israel but Europe and America more secure, Brown will surely have to support him.