In 1990, Buchanan published a newsletter called Patrick J. Buchanan: From the Right; it sent subscribers a bumper sticker reading: "Read Our Lips! No new taxes."
In 1990, Allan Ryan Jr., a former head of the OSI said Buchanan's accusation of KGB involvement in the Demjanjuk case was "an absolutely cockamamie theory." Ryan accused Buchanan of being "the spokesman for Nazi war criminals in America". Neal Sher, OSI head in 1990 said Buchanan had never contacted them, even when he was a government official. "He essentially took what was fed him by our opponents, sometimes Holocaust-deniers, and just regurgitated it," Sher told The Washington Post.
In a 1990 column for the New York Post, Buchanan wrote that it was impossible for 850,000 Jews to be killed by diesel exhaust fed into the gas chamber at Treblinka in a return to his interest in the Demjanjuk case. "Diesel engines do not emit enough carbon monoxide to kill anybody," he wrote. The Washington Post cited the belief of experts who said there is more than sufficient carbon monoxide present in the fumes to speedily asphyxiate victims causing their death. Buchanan once argued Treblinka "was not a death camp but a transit camp used as a 'pass-through point' for prisoners". In fact, some 900,000 Jews died at Treblinka. When George Will challenged him on the issue on TV in December 1991, Buchanan did not reply.
In the context of the Gulf War, on August 26, 1990, Buchanan appeared on The McLaughlin Group and said: "there are only two groups that are beating the drums for war in the Middle East – the Israeli defense ministry and its 'amen corner' in the United States." Buchanan on The McLaughlin Group on June 15 1990, asserted: "Capitol Hill is Israeli occupied territory". He also said in the August 1990 program: "The Israelis want this war desperately because they want the United States to destroy the Iraqi war machine. They want us to finish them off. They don't care about our relations with the Arab world." A.M. Rosenthal, in an article for The New York Times explicitly accused Buchanan of antisemitism on the grounds that he had used the word "Israelis" as a cover for Jews. Abraham Foxman, the director of the ADL, compared Buchanan's comments to insinuations made during the second world war "that Jews were the only ones who sought American entry in the war against Nazi Germany".
Holocaust survivor Elie Wiesel in September 1990 said Buchanan "leaves the memory of Jewish victims in such disdain; a man who always takes the side of those accused of being killers; a man who is constantly criticizing Israel; a man who always has something nasty to say about the Jewish people".