Recordings released last week by the Nixon Presidential Library contain some shocking comments made about Jews by former US Secretary of State Henry Kissinger.
In March 1973, following a state dinner at which then Israeli Prime Minister Golda Meir petitioned Mr Kissinger to encourage the USSR to allow Soviet Jews to emigrate to North America, Mr Kissinger said to President Richard Nixon: "If they want to put Jews into gas chambers in the Soviet Union, it is not an American concern. Maybe a humanitarian concern."
The disclosure has caused distress and outrage across the American Jewish world.
Martin Raffel, Senior Vice President of the Jewish Council for Public Affairs, called Mr Kissinger's comments "deeply disappointing".
"That a German Jew who fled the Nazis could speak of a genocidal outcome in such callous tones is truly chilling," said David Harris, Executive Director of the American Jewish Committee. "It's hard to find the right words to express the degree of our shock and revulsion at Kissinger's remarks."
It is chilling that a Jew who fled the Nazis could say this
Mr Kissinger, a winner of the Nobel Peace Prize, is also on tape saying that Jews share an inferiority complex: "Most Jewish people are insecure. And that's why they have to prove things."
Abraham Foxman, National Director of the Anti-Defamation League, was more forgiving. "The statements attributed to Henry Kissinger are unacceptable, disturbing, distressing and very painful," he said. "But even great people make mistakes.
"None of us can really understand the atmosphere that Kissinger worked in. He was surrounded by aides who were antisemitic and working with and for a president who was a bigot and a rabid antisemite. It doesn't justify or excuse him, but one needs to take it into account."
Following the release of the original Watergate tapes and a series of further recordings in 1999, Mr Nixon's antisemitic views have been well documented and his remarks have come as no surprise to Jewish organisations in the United States.
The latest recordings merely add to the charge sheet against Mr Nixon. His comments on American Jewry range from the assertion that "the Jews are just a very aggressive and abrasive and obnoxious personality," to personal attacks on Mr Kissinger, who he deems as insecure as "most Jewish people".
Mr Nixon is also heard to specify that no Jews who did not contribute financially to his presidential election campaign should be invited to a state dinner for Ms Meir.
Mr Foxman, however, argues that history will judge Mr Kissinger on the basis of his deeds rather than his words. "Henry contributed greatly to the defence of freedom and democracy in America and the West, as well as to the safety and security of Israel," he said.