"In its current form, anti-Zionism is worse than it has been in the past," said American foreign policy analyst Mitchell Bard.

And Mr Bard, the executive director of the American-Israeli Cooperative Enterprise, knows his stuff.

The author of numerous books on Israel and the Middle East, his latest tome, The Arab Lobby: The Invisible Alliance That Undermines America's Interests in the Middle East, describes how they exercise their influence in Washington's corridors of power.

"There is a growing worldwide movement of anti-Zionism that has gained acceptance," Mr Bard said.

"And there is a greater expectance of this notion - and it is a fundamentally antisemitic one - that Israel does not have the right to exist."

Born in North Carolina and raised in California in a secular and Zionist household, his father was the chairman of the local Israel Bonds.

He first experienced anti-Israel activity at the University of California, Santa Barbara, but "did not know how to respond to it".

But later, while studying at UC Berkeley and UCLA, he set up an Israel action committee.

Mitchell, 51, recalled: "I had spent a couple of weeks in Israel when I was 21 and had fallen in love with the place."

And his fight against anti-Israel extremism on campus continues today.

Seven years ago he started a project which brought the best Israeli scholars to teach at American universities.

"Berkeley is, always was and 20 years from now will still be a hotbed of anti-Zionism," Mitchell explained.

"When I started this campus project, in 2002, I realised that the main anti-Israel problems were actually coming from inside the classroom.

"There were few courses taught about Israel and the ones that were, were taught badly."

After completing a post-

doctoral fellowship at UC Irvine, where he researched the rescue by Israel of Ethiopian Jews, he worked as a polling analyst for George Bush senior during the 1988 presidential election.

Mitchell then landed a job as editor of the Near East Report, the American Israel Public Affairs Committee's weekly newsletter on US-Middle East policy.

He has authored and co-authored more than 20 books, and his Myths and Facts: A Guide to the Arab-Israeli Conflict has become a handbook for many novices who want to learn more about the Middle East.

Mitchell is also the director of the Jewish Virtual Library, an online encyclopaedia of Jewish history and culture.

But while such a strong supporter of Israel, he is mindful of the increasing Arab influence over Capitol Hill.

Hence his new book.

"The various small Arab American and Muslim American groups don't have a lot of influence on Washington," Mitchell explained.

"The main, more serious problem comes from the Saudi Arabian-led oil department. "Saudi Arabia undermines American values, they have an intolerant society, they practise discrimination and they undermine American interests.

"They have actually sabotaged American peace efforts in the Middle East.

"Saudi Arabia also supports terrorism, funds radical Islam education across the world and threatens Israel and other countries, as well as supporting terrorist groups such as Hamas."

Quite a diatribe, but is Mitchell perhaps being overly mistrustful?

"No, they are also involved in a lot of nefarious activities," he continued.

"America has had more than 70 years of relations with Saudi Arabia, with its large oil reserves.

"I think America, over that time, has been kowtowing to their interests."

Mitchell added that the Saudis are extremely adept at public relations.

"They are supportive of American interests when they don't threaten the Saudi regime, which is a dictatorship and a theocracy," he continued.

"The Saudis are well-known for their antisemitic statements and behaviour. Past monarchs have declared that the Jews use the blood of Muslims to make hamantaschen at Purim.

"And King Faisal, when he was in power, used to present visiting foreign dignitaries with the antisemitic book The Protocols of The Elders of Zion.

"The American state department has been unwilling to stand up to the Saudis."

There are numerous Arab American groups in America which lobby America but, Mitchell explained, they are less explicitly antisemitic and more extremely anti-Israel.

He said: "Their defining characteristics are, rather than lobbying for the rights of the Palestinians, they mostly lobby against Israel.

"One would expect their legislative agenda to lobby for a Palestinian state, for education - but they don't.

"They would rather campaign to cut aid off to Israel - to a degree they are cutting off their nose to spite their face."

Interestingly, the American-Arab Anti-Discrimination Committee, the largest Arab American civil rights organisation in America, asked AIPAC for training.

Mitchell, who lives in Maryland, said: "Groups such as them have a number of disadvantages - many Arab Americans are Lebanese Christians.

"There are many different ethnic groups within the Arab American community. They don't represent all Arab Americans, of which there are only three million.

"The American public does not support them either."

But what about Barack Obama being considered one of the most anti-Israel American presidents of recent memory?

Mitchell admitted that Obama's policies in his first year of office were not consistent with the interests of the Israel lobby.

"I don't think he is necessarily anti-Israel, but he doesn't have a clear foreign policy on Israel," he explained.

In contrast to the perceived Saudi influence over Congress, John Mearsheimer and Stephen Walt alleged in their controversial book The Israel Lobby and U.S Foreign Policy a disproportionate influence of Zionists over Congress.

And Mitchell admitted that the lobby does have some influence over certain policies.

But he slammed: "Mearsheimer and Walt hold crackpot theories.

"The lobby does sometimes gain access to decision makers in the state department and they can set general perimeters in which the president may operate.

"But they do not stop punitive measures and the lobby is not as severe as those two have made out."

The Arab Lobby: The Invisible Alliance That Undermines America's Interests in the Middle East is published by Harper, £17.65.