Say nothing about intelligence and NRBC-units. Agent Orange wasn't the only poison Americans used against Vietnamese people, you know.During the Vietnam War (1954–1973), Soviet involvement was indirect but significant. Soviet advisors and technicians operated surface-to-air missile (SAM) systems and trained North Vietnamese forces. Estimates suggest that approximately 3,000 American aircraft were shot down over North Vietnam, with a portion attributed to Soviet-operated SAMs.