Final answer:
President Johnson was confident in achieving U.S. goals through a plan aiming for a just and lasting peace influenced by progressive ideals and historical precedence, involving negotiations with North Vietnam and the potential return of U.S. troops.
Step-by-step explanation:
President Johnson was confident that the U.S. would achieve its goals because he believed in the comprehensive plan he had initiated to end the Vietnam War in a manner that would lead to a just and lasting peace. This plan involved starting negotiations with North Vietnam, pledging military and humanitarian assistance to South Vietnam, and signaling the possibility of US troops returning home. Moreover, Johnson's determination was influenced by the ideals of progressivism and the precedence of President Woodrow Wilson's peace efforts during World War I, which highlighted self-determination, free trade, and open diplomacy as keys to a stable peace. Johnson also remarked on the importance of using the nation's wealth to elevate American civilization, further underpinning his vision of success beyond the battlefield.