Vietnam Syndrome refers to the reluctance of the United States to engage in military interventions following the Vietnam War, due to the negative public perception and trauma associated with that conflict. It encapsulated the fear of becoming embroiled in another protracted and unpopular war, leading to a more cautious approach in U.S. foreign policy during the late 20th century. The term highlights the impact of public opinion on military strategy and decision-making in the aftermath of Vietnam.