The terrorist attacks of Sept. 11, 2001, are synonymous with wanton destruction. But they also produced an offshoot that seems virtually indestructible. In addition to causing massive loss of life, the attacks spawned a host of anti-Semitic conspiracy theories that implicated the Jews and Israel in the bloodshed. As it turns out, those canards were not fleeting expressions of paranoid fantasy that dissipated once they were debunked. On the contrary, nearly five years later, the various "Jews-did-it" scenarios emanating from the wreckage of the World Trade Center and the Pentagon have proven stubbornly resilient. "If anything, they're flourishing," says Chip Berlet, senior analyst at Political Research Associates, a liberal think tank based in Somerville, Mass. "The idea that Jews were somehow involved in 9/11 has now become a permanent feature in the conspiracy pantheon, like the JFK assassination and the Oklahoma City bombing," says Mark Pitcavage, director of fact-finding for the Anti-Defamation League. The phenomenon might seem baffling, if not disturbing, but its practical impact is unclear. The Internet is the chief incubator and disseminator of apocryphal 9/11 story lines, and cyberspace remains awash with chatter purporting to link the Jews with America's worst terrorist attacks, according to Pitcavage. But the same message, he added, is being spread through books, pamphlets, videos and speakers. The purveyors are an eclectic aggregation that spans the geopolitical spectrum. They include neo-Nazis and other white supremacists in the United States and elsewhere; anti-government zealots; young anti-war activists; Holocaust deniers; Lyndon Larouche supporters; New-Age ideologues; propagandists and journalists within the Arab and Muslim world; and assorted devotees of the early-20th-century forgery, "The Protocols of the Elders of Zion," which purports to document a Jewish plan to dominate the world. Efforts to connect the Jews with 9/11, however, are not limited to fringe groups talking with one another. Contributors to Wikipedia, the popular and influential online encyclopedia, have tried repeatedly to insert anti-Jewish 9/11 theories into Wikipedia's pages and represent them as fact or at least plausible versions of reality, according to Berlet. The insertions - which represent one of countless pieces of potentially suspect information submitted to Wikipedia almost daily - have been promptly excised by the encyclopedia's volunteer editors, says Berlet, himself a Wikipedia editor, "but it requires constant attention." It's impossible to determine how many viewers have seen the postings before they were removed from the Wikipedia Web site, which has a daily viewership of roughly 30 million, according to a company spokesman. The 9/11 assaults triggered an almost immediate outpouring of conspiracist conjecture, in part because of the bizarre, almost implausible nature of the attacks, according to Michael Barkun, a professor of political science at Syracuse University who has studied extremist movements and their philosophies. "These events cried out for some sort of explanation," Barkun says. "This was a golden opportunity for conspiracy theorists to introduce their theories to a broader audience. The thing to remember about conspiracy theories is that they are profoundly psychologically comforting. They give sense and meaning to the world. Nothing is arbitrary or accidental or coincidental." Not all of the explanatory hypotheses stemming from 9/11 implicate Jews. Some still accuse the United States government, for example, of being aware of the attacks and doing nothing to stop them in order to justify military intervention in the Muslim world. But anti-Semitic finger-pointing soon came to dominate the revisionist view of 9/11, according to a report issued in 2003 by the ADL. These accusations brought " 'The Protocols of the Elders of Zion' into the 21st century, updating a familiar theme: that Jews are inherently evil and have a 'master plan' to rule the world," says the report, which profiles the 9/11 conspiracists' cast of suspected plotters and other scapegoats. They include: â€¢ The Mossad, Israel's intelligence agency, which is accused of orchestrating and carrying out the attacks to advance the Jewish state's geopolitical agenda. "This perverse respect for the Mossad," the ADL report says, "derives in part from anti-Semitic notions that only Jews are sufficiently cunning, resourceful, and wicked to have carried out the attacks and blamed them on their enemies." â€¢ A "spy ring" consisting of young Israelis claiming to be art students. They purportedly had been tracking the 9/11 hijackers but did nothing to stop them. â€¢ Jewish businessmen, including owners of the World Trade Center, who plotted to destroy the structures to collect insurance money, thus perpetuating the "myth of the greedy Jew," the ADL report says. â€¢ "Four thousand Israelis" who allegedly worked at the World Trade Center but were warned by Israeli intelligence operatives to stay home on 9/11. One of the most widely accepted 9/11 myths, some sources say it was initiated by Hezbollah's Al-Manar television network. These assertions have been either laughed off as preposterous - or have been investigated and discredited. The "spy ring" story, for example, may have emanated from a disclosure that a number of young Israelis who violated their visas had been deported from the United States. Subsequent reports intimating that the deportees had been engaged in sinister, clandestine activities were examined by The Washington Post, among others, and found to be "nothing more than an urban myth," according to the ADL report. But the fact that conspiracy theories have been disproven is largely irrelevant to the theories' adherents, according to Barkun. The reason, he says, is that die-hard conspiracy-mongers are united by their embrace of what he calls "rejected knowledge." "These people are profoundly distrustful of authority. It seems absurd to the rest of us, but in the mirror world that conspiracy theorists live, anything that is rejected by mainstream institutions must therefore be true," Barkun says. A conspiracy-tinged view of world events seems to be gaining traction in America and elsewhere, according to Lou Manza, chairman of the psychology department at Lebanon Valley College in Annville, Pa. As evidence of this trend, he cites polls indicating that suspect theories of all kinds have gained popularity over the past 10 to 15 years. Among the possible explanations for this emerging worldview: In today's information-bloated environment, the conviction that all-powerful forces control global events makes life easier for believers by obviating the need to think critically about complex issues. "Our environment today is not conducive to a critical-thinking approach, especially with the instant access we have to so much information," Manza says. "If it's on the Internet and the graphics are good, it must be true." But why does it necessarily follow that the Jews in particular were the unseen hand behind America's most infamous terrorist attack? Because they had something to gain from 9/11, according to conspiracists, who contend that military retaliation against Arabs was its own reward for the Jews and Israel. Asked why the Jews were implicated in the attacks, Barkun says, "You might as well ask, 'Why does anti-Semitism exist?' Unfortunately, the concept is deeply rooted in Western culture. And like a lot of conspiracy theories, it's a closed system of ideas that is structured so that it's impossible to disprove." In a sense, the extremist explanations for 9/11 are merely an update of conspiracy theories that have been evolving ever since the Crusades, according to conservative columnist and analyst Daniel Pipes, director of the Middle East Forum, who has written two books examining conspiracy theories. Virtually every major conspiracy theory hatched over the past 900 years has featured one of two key elements, Pipes says. One is so-called "secret societies," such as the Trilateral Commission - an influential coalition of influential private citizens - as well as suspected government cabals; the other is the Jews. Anti-Semitic 9/11 scenarios have staying power, but it's unclear how widely they're embraced. In the West, according to Pipes and others, 9/11-related Judeophobia seems to have a limited constituency among both ordinary people and those in positions of power and influence. No American office-holder, for example, has tried to score political points by blaming the Jews for 9/11 - though recently defeated Rep. Cynthia McKinney (D-Ga.) made a name for herself by repeatedly taking anti-Israel stands and alleging that the federal government was complicit in the 9/11 attacks. All told, the Western strain of 9/11 revisionism seems dominated by conspiracy buffs rather than bona fide anti-Semites who pose a real danger to Jews, according to Pipes. Berlet takes a less benign view. "Any form of conspiracy theory is toxic to the democratic process," he says. "How can you reach compromise with those 'evil people' who bombed the World Trade Center? That sort of thinking could flare up in hard times and affect policy." Overtly anti-Semitic conspiracy theories stemming from 9/11 appear to be more widely accepted and tenacious in the Arab and Muslim world than in the West. "The implications in the Middle East are quite profound," Pipes says. "It's one more brick in the edifice of fear and loathing of Israel and the Jews."