Answer:
Many people were weary of war during the Vietnam War era because America had fought in three wars since the beginning of the 20th century, and many people did not see the rationale for getting involved in Vietnam.
The United States had been involved in World War I, World War II, and the Korean War, and many Americans were tired of the human and economic costs of war. Additionally, the Vietnam War was controversial from the outset, with many people questioning the government's rationale for getting involved in the conflict and the morality of the war itself. As the war dragged on and the human toll mounted, opposition to the war grew, and many people became disillusioned with the government and with American foreign policy more broadly. The anti-war movement became a major force in American politics, and it played a significant role in ending the war and shaping public opinion on military intervention in the decades that followed.