Roger Fisher was a specialist in conflict resolution through negotiation. One of his concepts was to look at both sides BATNA--best alternative to a negotiated agreement. McNaughton was his guy in the DOD. They were in large part responsible for the Johnson administration's strategy in Vietnam, which boiled down to showing the communist that they could not win. That is one reason why the "barrier" concept appealed to them.

The sensors that were to be used actually worked to the US advantage at the battle for the Khe Sanh combat base during the Tet offensive. However they were obviously not effective at cutting the Ho Chi Minh Trail because they ultimately relied on transitory power to effect an interdiction that required combat persisting force. One of the many weird rationales in the Vietnam war was the administrations position that it could use air power and small raiding forces in Laos to degrade the enemy's logistic train, but it would not permit a more effective use of force to stop the logistic train. The reason the sensor were effective in the Khe Sanh battle is that combat troops were in a position to stop the enemy's movement to contact in a combined arms effort.