A group of Soviet armed forces who were military specialists in Vietnam, came at the personal invitation of Ho Chi Minh to render military and engineering assistance to the Vietnamese People’s Army. From July 1965, to December 1974, more than 6,000 officers and more than 4,500 soldiers were sent to North Vietnam as specialists. The USSR claimed no soldiers fought in the war. The Soviets sent Vietnam money, arms, and military advisors. By comparison, over 2.7 million Americans served, defending south Vietnam during the war and more than 58,000 American troops died. Russian involvement was clearly minuscule by comparison, but there was indeed Russian involvement.
Starting in 1964, North Vietnamese fighter pilots and anti-aircraft gunners were being trained in the Soviet Union, with Soviet advisors also being stationed in North Vietnam. Soviet archives opened after the fall of the USSR indicate that Soviet crews manned the new Soviet anti-aircraft batteries given to the North Vietnamese troops, because the Vietnamese troops were still unfamiliar with how to use the new anti-aircraft guns. These Soviet gunners did in fact shoot down U.S. planes, with one such Soviet battery reportedly downing six U.S. planes. There were unconfirmed reports of Soviet snipers that embedded with NVA units and infiltrated South Vietnam to test their new SVD Dragunov sniper rifles. Witnesses described these snipers as white men with blue eyes.
Documents declassified by the USSR showed that a Soviet GRU Spetsnaz special forces unit took part in at least one, and likely more, ground combat operations. In 1968, a team of ten Spetsnaz attacked a covert U.S. base on the Cambodian-Vietnamese border, destroying three of the then-new U.S. Cobra attack helicopters and actually stealing another.
From 1968 on, North Vietnam received the vast majority of its military and economic aid from the Soviet Union in the form of food, petroleum, transport vehicles, iron, steel, fertilizer, arms, and ammunition. The Soviets supplied all of this as aid rather than loans. Without this aid, weapons and military advisors from the Soviet Union, the North Vietnamese would not have been able to sustain their war effort and would not have had as many successful operations against American troops.