I dunno. I can't claim anything approaching the expertise and experience of Mr. Burkett, but my judgment at this point is that Kennedy made a huge strategic error, circa 1960, when he decided to limit the fight to South Vietnam. Once North Vietnamese forces were ensconced in Laos and Cambodia they could supply South Vietnamese insurgents, or insert their own forces, virtually at will almost anywhere along the long Western border of South Vietnam. This made the war nearly impossible to win (with the level of forces it would be politically possible for America to contribute).
The correct strategy, IMHO, was to have fought the North Vietnamese in Laos. The Laotions hated the North Vietnamese, there was no analog to the significant ethnic North Vietnamese populations that existed in South Vietnam, and the North Vietnamese wouldn't have been able to sustain an insurgency as they did in South Vietnam. Thailand almost certainly could have been persuaded to support this effort. The necessary commitment of U.S. forces for this strategy would have been drastically lower than required for the strategy of defending South Vietnam from within.
As to the anti-war movement, as seditious as most of those bastards were during the phase of American involvement in Indochina, I personally think their most atrocious, shameful betrayals -- and those most damaging in the long term to American foreign policy -- came after:
Nixon came to office realizing that the country was indeed deeply divided about Vietnam, and that the well of political support for our efforts there would soon run dry. Therefore Nixon promised to extricate U.S. forces after concluding an honorable and sustainable peace agreement. This was basically a "deal" that was struck between the "hawks" and the "doves". The hawks in effect agreed to bring the troops home, and the doves in exchange agreed that this would satisfy them and in exchange they would support our allies and enforce a peace agreement (if it did not require recommitting U.S. ground troops).
In short Nixon and the hawks lived up to their end of the deal, and the doves utterly (and maliciously) failed to uphold their end. Nixon did bring the troops home, he did secure a peace agreement that if enforced would have allowed South Vietnam to survive, and Nixon (and later Ford) made every effort to secure the necessary aid to our allies in Indochina.
The doves claimed they only wanted to bring the troops home, but that was a lie. After every American soldier was safe they aggressively and gratuitously strong-armed through Congress cut after cut to aid, and restriction after restriction on operations necessary to enforce the peace. In the end aid to Cambodia was slashed to nothing, and even reconnaissance flights there were rendered illegal, and aid to South Vietnam was reduced to as near to nothing as made little difference. The South Vietnamese were rationing artillery shells even before they faced North Vietnamese regulars alone, and one of their main forces literally ran out of bullets during North Vietnam's final offensive.
This willful betrayal of an ally with a just claim on our support, let alone one two million American boys had fought for, and without being motivated by any countervailing American interest whatsoever, was monstrous. And what is worse it is portrayed as "honorable" even to this very day.
Their real motivation was to ensure that American purposes in resisting a "people's movement" (i.e. totalitarian communism and Vietmin hegemony) fail completely, finally and decisively. And never mind how many little yellow people had to be murdered in the process; the shaming and repudiation of America and her aims was more important.