FROM the forged “Protocols of the Elders of Zion” in the 19th century to the charter of Hamas, the Palestinians' Islamist movement, a common claim by anti-Semites has been that Jews trick great powers into needless wars. That is why an article published in March 2006 by two American academics, John Mearsheimer and Stephen Walt, caused such outrage. Writing in the London Review of Books, they argued that the activities of Israel and its supporters were the “critical” reason for America's invasion of Iraq. George Bush, Dick Cheney and Donald Rumsfeld may have thought that they were acting in America's interests, but were in fact acting in Israel's. Like previous American governments, the Bush administration had been turned by clever lobbying into what Lenin would have called Zionism's useful idiots.

This startling thesis is, to say the least, provocative. Since it implies that American boys are dying in Iraq for the sake of Israel, the authors must have known that it would stir up painful questions about the true loyalties of American Jews and therefore attract fiery criticism. But there is no evidence that Mr Mearsheimer and Mr Walt were motivated by any anti-Jewish prejudice. They say they want only to discuss a legitimate subject: the influence of the pro-Israel lobby on American foreign policy. Indeed, now that their article has grown into a book, they claim not only that they are not anti-Semitic but also that they are “pro-Israel”, in the sense that “we support its right to exist, admire its many achievements, want its citizens to enjoy secure and prosperous lives, and believe that the United States should come to Israel's aid if its survival is in danger.”

That a powerful pro-Israel lobby influences American policymaking in the Middle East, often for the worse, is indisputable. This book does a fair job of explaining how AIPAC, the American Israel Public Affairs Committee, along with like-minded lobbying groups and think-tanks, help to shape, and sometimes stifle, American thinking about the region. The authors have won plaudits for taking on this supposed “taboo” and enduring the inevitable opprobrium. Yet this portion of their argument is hardly groundbreaking: in Washington, the power of the lobby, so far from being a secret, is legendary. What is new is to accuse Israel's supporters of dragging America into Iraq. Here the authors are on much thinner ice.

Their thesis advances as follows. America and Israel enjoy an extraordinary special relationship. This cannot be because Israel is a strategic asset. Although there may have been a time during the cold war when Israel was a help, it has long since become a liability, because by supporting the Jewish state America alienates Arabs and makes itself into a target for terrorists.

Nor, they say, can American support be explained by some moral claim. Israel's existence is no longer in danger: far from being an underdog, it is the neighbourhood bully, denying statehood to the Palestinians and discriminating against its Arab minority. Since Israel is not useful to America and its behaviour is beastly, “something else must be behind the striking pattern of ever-increasing support”. That something, the authors conclude, must be the Israel lobby. By the same token, the lobby is the something that explains Mr Bush's otherwise “deeply puzzling” decision to topple Saddam Hussein in 2003. But for the lobby, “the war would almost certainly not have occurred”.

To contend that there can be no strategic or moral reason for Americans to support Israel is controversial on its own, but here at least the authors make a robust case. The same is not true of their attempt to blame Israel for the invasion of Iraq. The accusation is plain enough; but on further reading the clarity dissolves by stages into a muddle.

The muddle begins when the authors concede that those who pushed for the Iraq war genuinely expected it to benefit America as well as Israel. So the eye-catching implication in the headline—that Israel's supporters knowingly got America into a war that was in Israel's interest but not its own—is withdrawn in the fine print. Next, the authors admit that Israel, considering Iran the bigger threat, did not initiate the campaign for war against Iraq; it fell into line only after it realised that Mr Bush was already leaning that way, and that he would probably go on after Iraq to clobber Iran too. As for who persuaded Mr Bush to lean towards war, the authors say in a final confusing twist that the real driving force was not in fact the Israel lobby but “a small band of neoconservatives”.

Now if the small band of neoconservatives and the Israel lobby were the same thing, this might begin to make some sense. But they are not. At most, the two groups overlap. Many neocons are Jewish and most are favourable to Israel, but there are some who are neither. And a lot of the people whom the authors assign to the Israel lobby, such as former Clinton administration officials like Dennis Ross and Martin Indyk, would probably have conniptions on being called neocons.

How plausible, anyway, is blaming the war on the neocons? The Walt-Mearsheimer argument is that a lot of the neocons favoured an invasion even before 2001, but only after September 11th could they talk Mr Bush round, by offering a ready-made approach to the world at a time when he was trying to make sense of an unprecedented disaster. All the familiar suspects are marched out, among them Paul Wolfowitz and Douglas Feith, then at the Pentagon; Scooter Libby at the White House; John Bolton at State; academics such as Bernard Lewis at Princeton and Fouad Ajami at Johns Hopkins University; journalists such as Charles Krauthammer and Bill Kristol; and think-tankers such as Kenneth Pollack at Brookings.
Others did their bit

These people, it is true, argued in favour of the war. But so did others who were neither neocons nor Jewish nor any part of the Israel lobby—Britain's Tony Blair, say. The book makes no attempt to provide the principal actors' view of how the decision-making unfolded inside the Bush administration. And without a detailed account of this, the authors have no hard evidence on which to hang their central claim that the neocons' voices were the decisive ones.

As the Pentagon's number two, Mr Wolfowitz's views no doubt counted for something. But his boss, Mr Rumsfeld, was not a shrinking violet, no neocon and harboured no special love of Israel. Mr Lewis, a Jewish historian of Islam, may have enjoyed the odd meeting with Mr Bush, but it can be assumed that his vote did not outweigh that of Vice-President Cheney, a hard-headed “realist”. What tipped the balance for the president must be conjecture, but even after 484 pages it is hard to agree with Messrs Walt and Mearsheimer that it was Israel's interests that did it.

At one point the authors complain that Israel and its supporters in America are now rewriting history “to absolve Israel of any responsibility for the Iraq disaster”. But it was not Israel that invaded Iraq. Their own book feels like an attempt to absolve America of responsibility for a decision it took by, and for, itself.