At school, we were taught when our army came close to Cambodia's capital. The world and Cambodia government think we tried to conquer them, that’s why we returned as our goal was almost completed, take down The Khmer Rouge.
It started from 5/1975 to 12/1978 The Khmer Rouge with the aid of China, they used their army to attack our country, with the thought: “Just kill a few dozen a day, kill a few thousand every month, kill a few thousand a year, then you can fight 10, 15, to 20 years. Perform 1 kill 30, sacrifice 2 million Cambodians to destroy 50 million Vietnamese”
Toward 1975 our army focused on the south where America took place of the French to control the Sai Gon government (I believe It's because of communism and capitalism stuff) America used Vietnam’people to kill Vietnam’people.
Meanwhile, from 1972 The Khmer Rouge killed many soldiers at military distinct 9, and attacked the hospital of division 1 located at Takeo province. In the first six months of 1972, we recorded 26 cases our soldiers have been killed by The Khmer Rouge, 385 kidnaps, 413 goods confiscation. 1973 The Khmer Rouge caused 102 cases with attacked, killed, robbed.
On January 3, 1976, they increased their influence by attacked Gia Lai - Kon Tum province. Burned houses, looted, and kidnapped 130 villagers.
Toward June 1976, they also attacked the provinces of Long An, Binh Phuoc, and Tay Ninh.
Due to being hunted by The Khmer Rouge from 1975 to 1976, there were more than 15,000 Cambodia’people ran away from Cambodia to Vietnam to avoid being killed by The Khmer Rouge.
Border disputes and conflicts on May 4, 1975, the Khmer Rouge attacked Phu Quoc Island. Killed more than 500 innocent people. With anger, Hanoi counterattacked to regain these islands.
April 30, 1977, Pol Pot attacked 14/16 communes of An Giang province, destroyed many villages, schools, factories, killed many innocent people.
Even in the night, the Vietnamese 330th Division arrived in An Giang to counterattack and restore the areas occupied by the Khmer Rouge.
September 25, 1977, 9 divisions of the Khmer Rouge attacked the provinces of An Giang, Kien Giang, Long An, Dong Thap, Tay Ninh, many innocent people were killed, raped, burned houses, robbed 134 tons of rice, and much other crime.
December 31, 1977, Vietnam retaliated with 8 divisions, defeated 5 divisions of the Khmer Rouge, and approached Cambodia'Pray Veng province. And withdrew on January 5, 1978, which was taken as a warning to them. After that, Vietnam proposed a diplomatic solution to establish a demilitarized zone along the border, which Pol Pot refused.
December 31, 1977, Pol Pot unilaterally severed diplomatic relations with Vietnam, and fighting continued.
On February 1, 1978, the Central Committee of the Communist Party of Pol Pot held a meeting to discuss anti-Vietnam policy and decided to establish 15 divisions. Their resolution read: “Just kill a few dozen a day, kill a few thousand a month, kill a few thousand a year, then you can fight 10, 15, to 20 years. Kill 30 people 1 time, sacrifice 2 million Cambodians, kill 50 million Vietnamese. Pol Pot sent 13 of the 17 main divisions and several local regiments to attack continuously into Vietnamese territory, about 15–20 km deep.
During those attacks, the Khmer Rouge carried out massacres against the Vietnamese, one example being the Ba Chuc massacre in April 1978 that left 3,157 civilians killed, of which more than 100 families were killed. Between 1975 and 1978, up to 30,000 Vietnamese were murdered by the Khmer Rouge in the scope of their work. From May 1975 to December 23, 1978, the Khmer Rouge killed more than 5,230 Vietnamese civilians, wounded nearly 5,000, kidnapped or killed more than 20,000.
On February 5, 1978, the Government of Vietnam announced three points to suggest the two sides negotiate to avoid further bloodshed:
(1) Termination of military activities, withdrawal of armed forces 5 km from the border;
(2) Talks towards signing a treaty of possession and, without obsession, signing a treaty on the border;
(3) Agreement on a confidentiality agreement to format and secure international information and international surveillance.
Pol Pot refused, China refused to mediate, The United Nations did not respond to the Vietnamese government's protest against the Khmer Rouge's aggressive actions. Vietnam must turn to the use of force to resolve the conflict.
In fact, we helped Cambodians escape genocide.
For some reason, the user Goodi Shang deleted her comments, so I’ll put it here.