Escalation in Vietnam refers to the significant increase in U.S. military involvement in the Vietnam War during the 1960s, particularly under Presidents Lyndon B. Johnson and Richard Nixon. This term encapsulates the strategy of intensifying military operations and deploying more troops to combat the growing influence of communism in Southeast Asia, which was perceived as a threat to U.S. interests and global stability. The escalation strategy not only led to a rise in combat engagements but also sparked widespread protest and debate over U.S. foreign policy.