Final answer:
The Tet Offensive is falsely characterized as evidence of the winnability of the Vietnam War. Instead, it exposed the tenacity of the Viet Cong and prompted widespread American disillusionment with the war effort.
Step-by-step explanation:
The statement that the Tet Offensive demonstrated to the American people that Vietnam was a winnable war for the South Vietnamese and the United States is false. In actuality, the Tet Offensive highlighted the resilience and capability of the Viet Cong and North Vietnamese forces, calling into question the success of U.S. efforts in Vietnam. Despite inflicting substantial casualties on the Viet Cong, the Tet Offensive was a turning point in public opinion, with many Americans increasingly skeptical of the winnability of the war and the truthfulness of official reports. Graphic television coverage and the realization that the enemy could launch widespread attacks across South Vietnam, including the American embassy in Saigon, eroded the public's trust in the administration's policies and military strategy. Furthermore, the leaked Pentagon Papers and disturbing revelations about incidents such as the My Lai massacre solidified public opinion against the war, leading to intensified calls for U.S. withdrawal and contributing to President Johnson's decision to seek an end to the conflict.