The Tet Offensive was one of the largest military campaigns of the Vietnam War, launched on January 30 – March 28, 1968 by forces of the Viet Cong and North Vietnamese Army against the forces of South Vietnam, the United States, and their allies. It was a campaign of surprise attacks against military and civilian commands and control centers throughout South Vietnam. The Tet Offensive ended just days before Martin Luther King was assassinated and only 2 weeks before the 1968 Jewish Passover Lunar Eclipse.
The Tet Offensive created a crisis within the Johnson administration, which became increasingly unable to convince the American public that it had been a major defeat for the communists. The optimistic assessments made prior to the offensive by the administration and the Pentagon came under heavy criticism and ridicule as the “credibility gap” that had opened in 1967 widened into a chasm. President Johnson saw his approval rating plummet very quickly after the attack on American and Allied forces in Vietnam.
The shocks that reverberated from the battlefield continued to widen: On 18 February 1968 U.S Military posted the highest U.S. casualty figures for a single week during the entire Vietnam War: 543 killed and 2,547 wounded.As a result of the heavy fighting, 1968 went on to become the deadliest year of the war for the US forces with 16,592 soldiers killed.On 23 February the U.S. Selective Service System announced a new draft call for 48,000 men, the second highest of the war. On 28 February Robert S. McNamara, the Secretary of Defense who had overseen the escalation of the war in 1964–1965, but who had eventually turned against it, stepped down from office. By 1968, over 550,000 American soldiers were in Vietnam; during 1967 and 1968 they were being killed at the rate of 1,000 a month.
On March 31st 1968 just 2 weeks before the 1968 Jewish Passover Eclipse, President Lyndon Baines Johnson announced “I shall not seek and I will not accept the nomination of my party as your President.” Later, at a White House news conference, he said his decision was “completely irrevocable.