I the course of making a different point Richard Cohen casually recycles a lefty myth that was beaten down a few years ago:
How little the U.S. knows of war
I present you with a paradox. The U.S. Army that fought the Vietnam War was reviled, not spit upon (that's a myth)...
No, the Vietnam-era spitting is not a myth. Jerry Lembke wrote the book and articles making that claim. Prof. Lembke is an unreconstructed leftist who was a member of the Vietnam Veterans Against The War back in the day; in the early 90's he felt that the Vietnam-era hostility of peace protestors to US soldiers was being invoked to discredit protest against Desert Shield and Desert Storm. Consequently, he set out to rehabilitate his own youth and his fellow protestors. (Lembke's other attempt at rehabilitation was to argue that it was righties that invented the notion of the drug-addled, suicidal veteran in order to discredit protestors such as Lembke; this utterly ignores the former leader of his own organization, John Kerry, who went on at length about troubled vets in his famous 1973 Senate appearance.)
Lembke's work was simply politicized "social science" given a veneer of respectability by his academic credentials; it was never a serious attempt to understand the temper of the day.
Jack Shafer of Slate backed Lembke for a while but was eventually overpowered by the combination of reality and a reader revolt. Richard Cohen will no doubt escape a similar fate, since he has no apparent interest in reality.
SINCE NO ONE ASKED: Cohen's actual point is that the US military is becoming divorced from broader society, or at least, the society in which he circulates. Having ROTC back at the Ivies might help; having a Commander-in-Chief who can think of military service as a form of national service without being prodded might also be helpful. And, in a bit of a feedback loop, military basing decisions can be problematic.