George Soros, the billionaire investor, has added his voice to the debate over the role of Israel's lobby in shaping US foreign policy.
In the current issue of the New York Review of Books, Soros takes issue with "the pervasive influence of the American Israel Public Affairs Committee [AIPAC]" in Washington and says the Bush administration's close ties with Israel are obstacles to a peace deal between Israel and the Palestinians.
Soros, who is Jewish but not often engaged in Israeli affairs, echoed arguments that have fuelled debate in academia, foreign policy think tanks and parts of the US Jewish community.
"The pro-Israel lobby has been remarkably successful in suppressing criticism," wrote Soros. Politicians challenge it at their peril and dissenters risk personal vilification, he said.
AIPAC has consistently declined comment on such charges, but many of its supporters have been vocal in dismissing them.
Historian Michael Oren, speaking at AIPAC's 2007 conference in March, said the group was not merely a lobby for Israel. "It is the embodiment of a conviction as old as this (American) nation itself that belief in the Jewish state is tantamount to belief in these United States," he said in a keynote speech.
The long-simmering debate bubbled to the surface a year ago, when two prominent academics, Stephen Walt of Harvard and John Mearsheimer of the University of Chicago, published a 12,500-word essay entitled "The Israel Lobby" and featuring the fiercest criticism of AIPAC since it was founded in 1953.
AIPAC now has more than 100,000 members and is rated one of the most influential special interest groups in the United States, its political clout comparable with such lobbies as the National Rifle Association.
The AIPAC members are all US citizens and the group receives no funding from the Israeli government.
Its annual conference in Washington attracts a Who's Who of American politics, both Republicans and Democrats.
Mearsheimer and Walt said the lobby had persuaded successive administrations to align themselves too closely with Israel.
"The pro-Israel lobby has been remarkably successful in suppressing criticism"
George Soros, the billionaire investor
"The combination of unwavering support for Israel and the related effort to spread 'democracy' has inflamed Arab and Islamic opinion and jeopardised not only US security but much of the rest of the world," they wrote.
No other lobby group has managed to divert US foreign policy so far from the US national interest, while simultaneously convincing Americans that US interests and those of Israel are essentially identical, they wrote.
The two academics said that pressure from Israel and its lobby in Washington played an important role in President George Bush's decision to attack Iraq, an arch-enemy of Israel, in 2003.
Mearsheimer and Walt found no takers for their essay in the US publishing world. When it was eventually published in the London Review of Books, they noted it would be hard to imagine any mainstream media outlet in the United States publishing such a piece.
It has been drawing criticism that ranged from shoddy scholarship to anti-Semitism, chiefly from conservative fellow academics and political supporters of the present relationship between Washington and Israel.
In his contribution to the debate, Soros said: "A much-needed self-examination of American policy in the Middle East has started in this country; but it can't make much headway as long as AIPAC retains powerful influence in both the Democratic and Republican parties."
That influence is reflected by the fact that Israel is the largest recipient of US aid in the world.
Mearsheimer and Walt are now working on expanding their article into a book - to be published in September by Farrar, Straus and Giroux. The company has not commented on online reports that it paid the two authors a $750,000 advance and plans to print one million copies.
Another mainstream publisher, Simon and Schuster, already discovered that not only is it possible to publish criticism of Israel but it can also be good for the bottom line.
Former president Jimmy Carter's book "Palestine Peace Not Apartheid" shot up the bestseller lists after its publication last November; stayed there for more than three months and is still selling well.
It had an initial print run of 300,000 copies and there are now 485,000 copies in print, said Victoria Meyer, a spokeswoman for Simon and Schuster.
Carter's book and its reference to apartheid provoked angry reactions - more in the United States than in Israel, where leftists opposed to the occupation of the West Bank have been accusing the government of apartheid practices for years and where the word has lost its shock value.
In response to charges of bias and anti-Semitism, Carter said he wanted to provoke a discussion of issues debated routinely and freely in Israel but rarely in the United States.
"This reluctance to criticize any policies of the Israeli government is because of the extraordinary lobbying efforts of the American Israel Political Action Committee and the absence of any significant contrary voices," he wrote in the Los Angeles Times during a tour to promote his book. "It would be almost politically suicidal for members of Congress to espouse a balanced position between Israel and Palestine."
According to Oren, the pro-AIPAC historian, the Carter book and the Mearsheimer-Walt paper had the same "insidious thesis" and suffered from the same flaw - ignoring oil as a driving element in US policies on the Middle East.