What China’s last major war tells us about how it will fight the next one

• In February and March 1979, China fought a bloody three-week war with its smaller neighbor, Vietnam.
• China is considered to have underperformed in that conflict, and while China’s military is much different today, the Sino-Vietnamese War still has implications.
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On February 17, 1979, a massive 30-minute artillery barrage rocked the China-Vietnam border. They were the first of 880,000 shells that China’s People’s Liberation Army (PLA) would fire at its neighbor over the next three and a half weeks.

Within hours, some 200,000 Chinese soldiers crossed the border into Vietnam. They were supported by an additional 400,000 troops, hundreds of tanks, and 7,000 artillery pieces.

Their mission was to seize provincial capitals and obliterate any Vietnamese Army (PVA) forces in the areas between them. Despite initial breakthroughs, progress slowed, and the PLA found itself bogged down in a costly war in which it drastically underperformed.

Launched to “teach Vietnam a lesson,” as Chinese leader Deng Xiaoping claimed, the invasion was China’s first large-scale military action since the Korean War in 1953, and it remains the PLA’s last full-scale war to this day.

Inevitable conflict

The invasion surprised some in the West because China had been a steadfast supporter of Vietnam during its wars with France and the US. More than 300,000 PLA troops served in Vietnam between 1965 and 1969, with some 1,100 killed and 4,300 wounded. China also sent billions in aid to their communist brethren.

But tensions between the two communist "brothers" had been boiling for decades. Chinese domination in previous centuries left a general distrust of China in Vietnam, and border battles between China and the Soviet Union in 1969, during the Sino-Soviet split, made it clear to Vietnam that it would soon have to pick between its two benefactors.

Vietnam also faced rising tension and increasing border clashes with the murderous China-backed Khmer Rouge regime in neighboring Cambodia. That, along with Beijing's reluctance to send more aid to Hanoi, led Vietnam to side with the Soviets.

On November 3, 1978, Vietnam signed the Treaty of Friendship and Cooperation with the USSR. It wasn't an outright mutual-defense treaty, but it did include some security promises. Tensions escalated to the point where up to 150,000 Chinese living in Vietnam left for China.

All this was outrageous to Deng and the Chinese Communist Party (CCP), which viewed Vietnam as unappreciative and traitorous.

Most importantly, as the USSR already had a similar treaty with Mongolia, China felt at risk of being surrounded by the Soviets.

By December 7, China's Central Military Commission had decided to launch a limited war along the border. At the end of that month, Vietnam invaded Cambodia to oust the Khmer Rouge.

Severe underperformance

Despite a two-to-one advantage in forces and the eventual completion of its military objectives, the PLA severely underperformed.

With very little overall training and virtually no combined-arms training, many PLA attacks were uncoordinated human-wave assaults, leading to high casualties and prolonging the battles.

PLA soldiers were so undertrained that there were reports of infantrymen tying themselves to tanks with ropes to avoid falling off, sealing their fate when they were ambushed.

Conversely, some tank units didn't know how to communicate with infantry at all, leading to them going into battle alone or with little coordination, which allowed experienced Vietnamese tank-killing teams to pick them off. The Vietnamese later claimed to have destroyed or damaged at least 280 tanks and armored vehicles during the war.

Worse for the PLA, Deng had forbidden the use of the Air Force and Navy so as to not risk escalation with the Soviets. The PLA was especially worried its Air Force would be soundly beaten by experienced Vietnamese pilots, who had dogfighting experience against the best in the world, the US Air Force.

Casualties and lessons

After about two weeks of fighting, the PLA began its withdrawal.

By March 16, its forces had crossed back into China, but not before enacting a scorched-earth campaign in Vietnam, thoroughly destroying or looting anything of value, including factories, bridges, mines, farms, vehicles, and even crops.

Neither China nor Vietnam, known for keeping battlefield losses secret, ever officially disclosed their casualties, though each claimed to have inflicted large numbers of casualties on the other. China said its forces killed or wounded up 57,000 Vietnamese troops, while Vietnam claimed over 60,000 PLA killed or wounded.

More reliable estimates for Chinese losses range from 7,900 to as many as 26,000 troops killed, with about 23,000 to 37,000 wounded. Estimates for Vietnam range from 20,000 to 50,000 soldiers and civilians killed and wounded.

The high number of casualties in such a short period is staggering, especially since Vietnam's militia and second-tier troops did most of the fighting, as many elite Vietnamese forces were fighting in Cambodia.

But to Deng Xiaoping, the high casualties were not entirely surprising. One of Deng's motivations for the war was so the PLA could gain badly needed experience.

Deng himself had a low opinion of the PLA, calling it "swollen, slack, arrogant, extravagant and lazy." He used the poor performance as a lesson and justification for massive reforms and modernization of the PLA.

Legacy and future

The war is largely unacknowledged by the Chinese public today.

"The main reason is that the CCP is reluctant to talk about that conflict," Timothy Heath, a senior international and defense researcher at the Rand Corporation think tank, told Insider.

Celebrating the conflict is awkward for the CCP, especially as Beijing tries to reduce its neighbors' suspicions about its intentions.

The fact that China was the aggressor "goes against the message that the CCP tries to promote - that China is always a peaceful power, never initiates attacks, and only responds defensively," Heath said. The PLA's poor performance would also put a damper on any celebrations.

Because the PLA today is different in virtually every aspect, and because China's Air Force and Navy were forbidden from fighting, the war does not really provide a good example for how the PLA may perform on the modern battlefield.

But the political motivations and implications of the war are still very relevant.

"China was willing to carry out aggression against this country, this neighbor, to send a message that alliances with an outside power that China regards as threatening is something that China is willing to fight over," Heath said.

"That is a message to bear in mind as the US builds its alliances and partnerships around Asia, and competition between China intensifies," he added.

The Soviets did send high-ranking military officials to help organize Vietnam's defense and deployed additional ships into the South China Sea, but they did not enter the conflict. Years later, the Soviets pressured Vietnam to engage with China diplomatically, leading to Vietnam pulling out of Cambodia in 1989.

The limits of superpower support is extremely important for Taiwan, which the CCP routinely threatens to reabsorb, potentially by force. If Taiwan were attacked and the US sat it out, as the Soviets did in Vietnam in 1979, it may prove fatal for the island nation.

While it avoids discussing its experience in Vietnam, Beijing remains acutely aware of its performance.

"My suspicion is that the ghosts of those battlefield failures still haunt the PLA, and they still must have some degree of anxiety about how will they perform on the battlefield." Heath said. "Everybody has a right to be skeptical about how well the PLA can possibly perform on the battlefield given their last known demonstration was pretty