Second, these scholars contend that the influence within the Bush administration of the Israel lobby has been magnified by its "junior partner," the Christian Zionists. In theological terms, they are talking about premillennial dispensationalists -- people who believe that the success of the state of Israel is a welcome sign of the end times.

The views of dispensationalists are broadly disputed by serious, conservative Protestant scholars. I don't share those views. I can't imagine that the president or the secretary of state shares them -- but I would not know for sure because I never once heard such views advocated or mentioned in five years of policy discussions I participated in at the White House.

There is a temptation in some academic circles to search for that mysterious key that will unlock our whole understanding of American foreign policy. George Bush is captive to the Israelis, or maybe Dick Cheney is captive to the Saudi Arabians. The real problem is the Israeli lobby on the grassy knoll, or dispensationalists covering up the Da Vinci code.

But all this is a conspiracy against the obvious. Perhaps many Americans actually prefer Israel's flawed democracy to the aging autocrats and corrupt monarchies of the region. Perhaps they root for a reliable ally that is surrounded by nations still committed to its destruction. Perhaps many Americans recall that the Jews, just six decades ago, lost one-third of their number to genocide and believe that this persecuted people deserves a secure home and sanctuary. Perhaps Americans understand that anti-Semitism was the greatest source of evil in the 20th century and is not dead in this one.

Walt and Mearsheimer are careful to say they are not anti-Semitic or conspiracy-minded. But their main inference -- that Israel, the Israel lobby and Jewish neoconservatives called the shots for Bush, Cheney, Condoleezza Rice, Stephen Hadley, Colin Powell and Donald Rumsfeld -- is not only rubbish, it is dangerous rubbish. As "mainstream" scholars, Walt and Mearsheimer cannot avoid the historical pedigree of this kind of charge. Every generation has seen accusations that Jews have dual loyalties, promote war and secretly control political structures.

These academics may not follow their claims all the way to anti-Semitism. But this is the way it begins. This is the way it always begins.