The Real Cuban Missile Crisis - Benjamin Schwarz - The Atlantic:
Although Kennedy in fact agreed to the missile swap and, with Khrushchev, helped settle the confrontation maturely, the legacy of that confrontation was nonetheless pernicious. By successfully hiding the deal from the vice president, from a generation of foreign-policy makers and strategists, and from the American public, Kennedy and his team reinforced the dangerous notion that firmness in the face of what the United States construes as aggression, and the graduated escalation of military threats and action in countering that aggression, makes for a successful national-security strategy—really, all but defines it.
The president and his advisers also reinforced the concomitant view that America should define a threat not merely as circumstances and forces that directly jeopardize the safety of the country, but as circumstances and forces that might indirectly compel potential allies or enemies to question America’s resolve. This recondite calculation led to the American disaster in Vietnam: in attempting to explain how the loss of the strategically inconsequential country of South Vietnam might weaken American credibility and thereby threaten the country’s security, one of McNamara’s closest aides, Assistant Secretary of Defense John McNaughton, allowed that “it takes some sophistication to see how Vietnam automatically involves” our vital interests.