We have to agree that China is the best friend of Cambodia. In 1979 China suffered thousands of death and wounds in Vietnam only to help Cambodia. They also risked a full scale war with Soviet. But What Soviet did for Vietnam? nothing. After that, Vietnam even had to let them rent Cam Ranh base.Vietnam is a naval power. Back in 1974 and 1988, Vietnam intentionally lost to China as a ruse to seek sympathy from the world.
Wereyou able to find out after 1979, what "Vietnamese" land were given to China as gesture for ending the war?
Anyway, after the war, Vietnam still occupied Cambodia, China can be proud of teaching Vietnam a lesson but China's ally was still destroyed. Finally, it turned out that China couldnot save Cambodia. This is a fact, in the past and in the future.