Today marks the 50th anniversary of the Tet Offensive, a major turning point in the Vietnam War. Tet is primarily remembered as the event that exposed the Johnson Administration’s failed war policy in Vietnam. But Tet also had a lasting impact on guerrilla tactics, a legacy that has had disturbing ramifications for the laws of war.
On the night of January 30, 1968, about 80,000 North Vietnamese Army troops and Viet Cong guerrillas launched a massive assault on over 100 American and South Vietnamese military bases and government facilities throughout South Vietnam. A squad of Viet Cong troops even made it onto the grounds of the U.S. Embassy in Saigon, engaging in a sustained firefight with U.S. Marines and U.S. Army soldiers. The next day television footage of dead Viet Cong troops sprawled across the embassy grounds led news broadcasts in the United States and across the world.
The first night’s fighting represented the opening round of an offensive that would rage for weeks and cost tens of thousands of lives. Although Tet ended in a decisive American and South Vietnamese military victory over the NVA and Viet Cong, the fact that the communist forces had the strength to launch such a huge onslaught severely undermined popular support in the U.S. for the war effort. Tet made clear that there was no end in sight to the Vietnam War. In the weeks afterward, President Lyndon Johnson announced that he would not run for reelection. Tet prompted even the hawkish Republican candidate Richard Nixon to promise to bring an “honorable” end to the war. The long and bloody path to American withdrawal from South Vietnam thus began amid the chaotic violence of the Tet Offensive.
But there is another side of Tet that is too often overlooked. One reason why the communist forces achieved tactical surprise during the Tet Offensive, and penetrated as far as the U.S. Embassy, was the fact that many of the Viet Cong troops wore civilian clothing, not military uniforms. Wearing civilian attire gave the Viet Cong a huge tactical advantage. They could hide in plain sight among the South Vietnamese civilian population, and then strike without warning on unsuspecting American and South Vietnamese troops. After they attacked their targets, the Viet Cong melted back into the civilian population to fight another day.
As a direct result of such tactics, one of the enduring images of the war is that of confused, frightened, and frustrated American troops struggling to distinguish South Vietnamese civilians from Viet Cong guerilla fighters.
Although the use of civilian clothing was a highly effective tactic for the Viet Cong, it was also a clear-cut violation of the laws of war. The reason is simple: combatants must not blur the line between combatant and non-combatant. An attacker who wears civilian clothing places true civilians at enormous risk because defending forces cannot accurately distinguish between combatant and non-combatant when returning fire.
Accordingly, the practice of engaging in combat while wearing civilian attire has long been prohibited under international law as an act of perfidy. Article I of the Annex to the 1899 Hague Conventions, the first major codification of the international laws of war, requires combatants to wear “a fixed distinctive emblem recognizable at a distance” and further requires that combatants carry their “arms openly.” Moreover, the 1949 Geneva Conventions expressly extended the provisions of the 1899 Hague Conventions to guerrilla forces. Article 4(A)(2) of Geneva Convention III requires irregular forces—including members of “organized resistance movements”—to wear a “fixed distinctive emblem recognizable at a distance” and to “carry arms openly.” Attackers who use civilian clothing to launch a sneak attack on their targets forfeit their right to Prisoner of War status under the Geneva Conventions.
The tactics employed by the communist forces in the Tet Offensive were far from their only international law violations. At the Battle of Hue, communist troops perpetrated mass executions of thousands of South Vietnamese civilians, the worst but by no means the only episode of North Vietnamese and Viet Cong troops murdering innocent non-combatants. Both the NVA and the Viet Cong routinely engaged American troops in populated areas so as to maximize the likelihood that South Vietnamese civilians would be caught up in the crossfire. The North Vietnamese also systematically tortured South Vietnamese and American prisoners of war, including Navy pilot and future Senator John McCain.
But it is undeniably true that the United States military also engaged in widespread violations of the laws of war in Vietnam. The most notorious case was the My Lai massacre in 1968, when a U.S. Army platoon murdered 500 innocent South Vietnamese villagers, including babies and toddlers. Post-war investigations would find evidence of many other atrocities committed by American troops, which the Pentagon had routinely covered up.
Most devastating of all, the Americans’ heavy reliance on airpower to support ground operations played directly into the communist strategy of placing South Vietnamese civilians in the line of fire. Indeed, the entire American military strategy in South East Asia showed callous disregard for civilian lives, including ironically the lives of South Vietnamese civilians, the very people that the United States said it intervened to defend.
In short, Vietnam was a war that saw civilians victimized on a massive scale by all parties to the conflict.
But, from the standpoint of international law, perhaps the most enduring legacy of Vietnam is the war’s central—and deeply disturbing—lesson for insurgent forces around the globe. As the Tet Offensive demonstrated in stunning fashion, irregular forces that conceal their identity by blurring the distinction between civilian and combatant gain a critical tactical advantage, one so great it can even neutralize the enormous technological capabilities and firepower of the United States armed forces, the most powerful military in the world.
Insurgents around the world have taken note of Tet’s lessons, as both the Iraq and Afghanistan wars have revealed. Consequently, despite the efforts of the Geneva and Hague conventions to protect civilians, on the modern battlefield it is harder than ever to distinguish between combatants and non-combatants. That may be the Tet Offensive’s grimmest legacy of all.