The vision or lack of it impacted the perception of the Vietnam War's with the American Public. President Johnson found that the metric for success in the conflict was constantly changing. With the introduction of Rolling Thunder and air mission bombings, there never came a clearly communicated vision as to what would constitute victory in the region. The United States entry was made clear to the public, yet how entry was to constitute victory was never clearly articulated to the public.
From a political standpoint, this caused a lack of credibility with the public. It also began to feed the idea that the war was miscalculated and that the government could not clearly control it as government lacked a vision. This was enhanced within President Johnson's own cabinet: there were questions within as to what constituted victory and how victory was to be measured. Secretary of Defense McNamara provides one such example. Being in a position as Secretary of Defense of having his name attached to the war, he later moved to speaking out against it towards the end of his term of service. McNamara himself thus embodied how the lack of vision in Vietnam eventually impacted the perception of the war.
The gradual increase in US military commitment in Vietnam further reflected a lack of vision. The arrival of combat troops, Westmoreland's plan, the recalibration after the Tet Offensive are all examples of this. In each of these, the lack of vision was definite, contributing to results that could not be properly assessed. This lack of vision fed the larger narrative that there was no definite exit strategy and that the war was no longer being controlled in that it was controlling everyone involved. The inability to communicate a clear policy of victory and, thus, a clear vision helped to feed the larger understanding that the war was a mistake. This assessment was something to which President Johnson grimly capitulated in not seeking reelection in 1968.