Vietnam stab-in-the-back myth

The Vietnam stab-in-the-back myth asserts that the United States' defeat during the Vietnam War was caused by various American groups, such as civilian policymakers, the media, antiwar protesters, the United States Congress, or political liberals.

Used primarily by right-wing war hawks, the name "stab-in-the-back" is analogous to the German stab-in-the-back myth, which claims that internal forces caused the German defeat during World War I. Unlike the German myth, the American variant nearly always lacks an anti-Semitic aspect. Jeffrey Kimball wrote that the United States' defeat "produced a powerful myth of betrayal that was analogous to the archetypal Dolchstoßlegende of post-World War I Germany."

The myth was a "stronger version of the argument that antiwar protest encouraged the enemy, suggested that the antiwar movement might in the end commit the ultimate act of treachery, causing the loss of an otherwise winnable war."