Shortly before publication, it emerged in the press that Hersh had removed claims at the last minute which were based on forged documents provided to him by fraudster Lex Cusack, including a fake hush money contract between Kennedy and Marilyn Monroe. An article about the controversy in The Washington Post said: "The strange and twisted saga of the JFK file is part cautionary tale, part slapstick farce, a story of deception and self-delusion in the service of commerce and journalism". Hersh and a one-time co-author had received a $800,000 advance for the project. Other aspects of the book also came under criticism, including its prying into Kennedy's alleged sexual escapades based on interviews with his Secret Service guards, and its claim that Kennedy used Judith Exner as a courier to deliver cash to mobster Sam Giancana, made by a source who later recanted it before the Assassination Records Review Board. In 1998, Hersh published Against All Enemies: Gulf War Syndrome: The War Between America's Ailing Veterans and Their Government, about Gulf War syndrome. He estimated that 15 percent of returning American troops were afflicted with the chronic and multi-symptomatic disorder, and challenged the government claim that they were suffering from war fatigue, as opposed to the effects of a chemical or biological weapon. He suggested the smoke from the destruction of a weapon depot that stored nerve gas at Khamisiyah in Iraq, which more than 100,000 soldiers were exposed to, as a possible cause. Later investigations Starting in 1993, Hersh was a regular contributor to The New Yorker. An article he wrote that year, based on his interviews with former CIA deputy director Richard J. Kerr, revealed how Pakistan acquired nuclear weapons with the consent of the Reagan and Bush administrations, and using material purchased in the U.S. In 2000, Hersh wrote a 25,000-word article which detailed an alleged massacre of Iraqi troops by soldiers under General Barry McCaffrey in the last days of the 1990–1991 Gulf War, at the Battle of Rumaila. Hersh performed six months of research for the story, and interviewed 300 people, including soldiers who had witnessed the killing. In July 2001, the magazine published Hersh's investigation of Mobil's illegal activities in Kazakhstan in the 1990s. Following the September 11, 2001, terrorist attacks, Hersh turned his focus to U.S. policy in the Middle East and the Bush administration's "war on terror". In The New Yorker, he