Why did Viet Nam invade China?

Reason: China and the United States began to contact in the 1970s, which made the Soviet Union feel a "major threat". The Soviet Union accelerated the wooing of Vietnam, prompting Vietnam to invest in the Soviet Union quickly, and immediately began anti-China actions after the reunification of North and South. China persecuted overseas Chinese at home and harassed China's border abroad, which further strengthened Vietnamese self-confidence and ambition.

1February 1979 17 to March 1979 16, the border guards of the China People's Liberation Army fought back in self-defense against the Vietnamese regional hegemonists who constantly violated our territory.

With the encouragement and support of the Soviet Union, the Vietnamese authorities, out of the ambition of national expansionism, acted treacherously, regarded China as the "number one enemy", madly opposed China and excluded China, and constantly carried out armed aggression and provocation against China.

Vietnamese troops invaded our territory, destroyed our villages and killed our soldiers and civilians, which seriously threatened and destroyed the security and socialist construction in our border areas. The China government warned and protested many times, but the Vietnamese authorities ignored it. Our border guards couldn't bear it anymore, and were ordered to launch a punitive self-defense counterattack against the Vietnamese invaders on February 17, 2007.

During more than 20 days of fighting, our border guards attacked four regular divisions 10 regiment of the Vietnamese army, killing more than 37,300 people and capturing more than 2,200 people. They seized a large number of weapons and equipment and combat materials, destroyed a large number of military facilities built in northern Vietnam against China, and dealt a powerful blow to the Vietnamese aggressors. Politically and militarily, it has achieved great victory. After completing the expected purpose, all Chinese border guards withdrew to China on March 16.

Extended data:

1979, China returned to Vietnam in self-defense, which achieved the expected operational purpose, disrupted Su Yue's strategic deployment, and destroyed the industry and mining industry in northern Vietnam, which was of great significance to protecting China's national sovereignty and territorial integrity, as well as peace and stability in Southeast Asia and even the world.

Vietnam also became exhausted after this war. After ten years of round fighting, the People's Liberation Army has trained a group of outstanding commanding talents and exercised its combat capability. During the war, China occupied most of the border cycling points, advanced the border signed by the Qing government and France in the late Qing Dynasty, and controlled the vast strategic commanding heights in the border areas between China and Vietnam, which was confirmed in the Sino-Vietnamese Land Border Treaty of 1999.

Baidu Encyclopedia-Self-defense counterattack against Vietnam (China-Vietnam border self-defense counterattack)