The level of detail here often went over my head, as my knowledge about the Vietnam War is low. However, a fundamental point is that US academia bears the mark of shame of having many apologists for (and even architects of) the most despicable of US foreign policies. These apologists apply their 'scholarly caution' in a selective way aimed not at truth-seeking, but rather at dismissing anti-war activists as uncritical, irrational, or naive.
Chomsky identifies not only "a growing lack of concern for truth" among academics in the US, but also "a real or feigned naiveté about American actions that reaches startling proportions". He also targets the 'pious rhetoric' about the supposed benevolence of US foreign policy, showing (with direct quotes) that policymakers are in fact willing to murder hundreds of thousands to extend the nation's power and influence. Rather than limiting himself to a broad, vague critique, Chomsky importantly singles out particular scholars, lambasting their "expert" input on the Vietnam War and drawing attention to their increasingly cozy relationships with Washington.
Here are a few quotes that caught my attention:
"[...]the power of the government’s propaganda apparatus is such that the citizen who does not undertake a research project on the subject can hardly hope to confront government pronouncements with fact."
"No one would be disturbed by an analysis of the political behavior of the Russians, French, or Tanzanians questioning their motives and interpreting their actions by the long-range interests concealed behind their official rhetoric. But it is an article of faith that American motives are pure, and not subject to analysis"
"Nothing is said about those people in Asian cultures to whom our 'conception of the proper relation of the individual to the state' may not be the uniquely important value, people who might, for example, be concerned with preserving the “dignity of the individual” against concentrations of foreign or domestic capital, or against semi-feudal structures (such as Trujillo-type dictatorships) introduced or kept in power by American arms."
"A striking feature of the recent debate on Southeast Asian policy has been the distinction that is commonly drawn between 'responsible criticism,' on the one hand, and 'sentimental,' or 'emotional,' or 'hysterical' criticism, on the other. There is much to be learned from a careful study of the terms in which this distinction is drawn. The 'hysterical critics' are to be identified, apparently, by their irrational refusal to accept one fundamental political axiom, namely that the United States has the right to extend its power and control without limit, insofar as is feasible."
"Is the purity of American motives a matter that is beyond discussion, or that is irrelevant to discussion?"
"[...]the fundamental political axiom that the United States, with its traditional concern for the rights of the weak and downtrodden, and with its unique insight into the proper mode of development for backward countries, must have the courage and the persistence to impose its will by force until such time as other nations are prepared to accept these truths—or simply, to abandon hope."
"The aggressiveness of liberal imperialism is not that of Nazi Germany, though the distinction may seem academic to a Vietnamese peasant who is being gassed or incinerated."
"Recent history shows that it makes little difference to us what form of government a country has so long as it remains an 'open society,' in our peculiar sense of this term—that is, a society that remains open to American economic penetration or political control."
"In fact, few imperialist powers have had explicit territorial ambitions. Thus in 1784, the British Parliament announced: 'To pursue schemes of conquest and extension of dominion in India are measures repugnant to the wish, honor, and policy of this nation.' Shortly after this, the conquest of India was in full swing."