There’s no army on earth more anti-Communist than that of South Korea. When your closest neighbor and mortal enemy is North Korea, there’s just no other way. South Korea, also known as the Republic of Korea, suffered heavily from the surprise invasion from the north that started the three year long Korean War. The south has been willing to fight communism anywhere in the world ever since.
When the United States intervened in the war in Vietnam, one of the earliest allies to send combat troops was the Republic of Korea. When the ROK 2nd Marine Brigade arrived in October 1965, its commander made sure the North Vietnamese and Viet Cong knew who they were going up against.
“We have only one purpose here — combat,” he said. He went on to say that they would be ready to fight any communist “anywhere, anytime.” And they were.
A total of 37,000 Korean Marines would find their way to the battlefields of Vietnam and they were able to accomplish what other allies could not. Korea’s 2nd Battalion took over the assault on Ca Tau Mountain in November 1965. It was a heavily fortified position that the North had held for more than 18 years. The French couldn’t take it. The South Vietnamese failed to take it. The South Koreans took it in just nine hours.
Everywhere South Korean Marines went, they cleared entire areas of communist aggression, securing rice fields, ports and the flanks of U.S. and South Vietnamese allies. In February 1966, the NVA attacked the Korean 3rd Marine Division at Tra Binh Dong. The Koreans held off the advance, despite being outnumbered 5-to-1.
What they did next would likely embed itself in the minds of communnist forces in Vietnam anytime they considered fighting South Korean Marines.
More than 2,400 North Vietnamese soldiers pressed their attack but were pushed back – until the Marines ran out of ammunition. Once the shooting from the Marines stopped, the communists charged the Korean lines. Where other armies might have broken off or retreated, the Marines stayed put.
When the NVA poured through the Korean defenses, they found a force armed with fixed bayonets, pickaxes, and entrenching tools, which the Koreans used to such devastating effect that that forced the advancing communists back out of their perimeter.
Upon returning to their lines, the Koreans detonated charges they’d set up around their camp. If the NVA planned an orderly withdrawal, that plan was now out the window. The Marines decided they would box in their enemy with the controlled detonation.
The NVA also quickly found out that the Koreans weren’t completely out of ammunition. A detachment of Marines had left the perimeter and taken out the NVA’s mortar company. The communists tried one last time to charge the perimeter, but by then the detachment had returned and the NVA attacked a line that exploded with machine gun fire, cutting them down.
What should have been an easy victory for the North Vietnamese Army turned into a total disaster, killing a tenth of the attacking force. Half of the communist dead were actually killed in the hand to hand fighting inside the Marines perimeter. The South Koreans lost 15 of their own, but the NVA didn’t try another offensive in the area until after the Korean Marines departed.