Here is the best explanation I've seen yet of Chomsky's (Cockburn's, Monbiot's ...) extreme hostility to 911 Truth, JFK assassination Truth etc:
Robert Fisk on 9/11 Truth: Good Beginning <http://bleiersblog.blogspot.com/2007/09/carl-lesnor-robert-fisk-on-911-\ truth.html> By Carl Lesnor September 2007 ... Those who considered Kennedy merely another servant of an omnipotent ruling class denied that its agents would have any interest in killing him. ([Noam Chomsky and Alexander Cockburn maintain this position to this day.)*[ii] ... [ii] Cockburn still believes in the Warren Commission and its 'magic bullet.' He makes his political motives quite clear: "These days a dwindling number of leftists learn their political economy from Marx..." a fact he deplores. If they had they would have been able to resist the "diffuse, peripatic (sic) conspiracist view of the world that tends to locate ruling class devilry not in the crises of capital accumulation, or the falling rate of profit, or inter-imperial competition, but in locale (the Bohemian Grove, Bilderberg, Ditchley, Davos) or supposedly "rogue" agencies, with the CIA still at the head of the list." http://www.counterpunch.org/cockburn11282006.html As he makes very clear, his refusal to examine the evidence is rooted in his a priori view that everything can and ought to be explained in terms of Marxist theories of vast anonymous forces such as capitalist accumulation and the falling rate of profit. Conspiracies, he thinks, are more to the taste of "the libertarian and populist right" which "mistrusts government to a far greater degree than the left..." Obviously, after mastering Volume Three of Capital, one has no need of empirical evidence, even if Marx never did get around to writing his book on the State. Cockburn -- as well as Chomsky -- know in advance that all US presidents are all equally servants of ruling class interests and that therefore it wouldn't make any political sense to assassinate them, ergo an assassination is merely a fait diversr [current event], devoid of political significance, ergo the bullets all came from the sixth floor of the Book Depository. Cockburn also asks: What do we make of Osama taking credit for the attacks? That he's still on the CIA payroll?" The fact is that Osama explicitly denied having anything to do with the attacks and indeed condemned them. http://www.robert-fisk.com/usama_interview_ummat.htm After denying and condemning it publicly, he then is supposed to have made a private video, claiming credit for what he publicly denied, and condemned, and somehow allowed it to fall into the hands of the Americans