In January 1968, US and south Vietnamese forces faced their biggest battles yet. The US Marine base at Khe Sanh, on the DMZ, came under siege from 40,000 NVA troops hoping to create an American Dien Bien Phu type defeat. Simultaneously VC forces violated the traditional Tet New Year truce and attacked dozens of provincial capitals in the South. US and ARVN forces ultimately crushed the offensive after 3 weeks, but not before the enemy had won a psychological victory from anti-war forces at home in the USA (the American people had been told for 3 years that the USA and South vietnam were winning and had the enemy on the ropes - the offensive proved the opposite was true).
From the documentary "Letters Home from Vietnam", features the voices of actors Randy Quaid and Harvey Keitel among others