The Vietnam War (Vietnamese: Chiến tranh Việt Nam), also known ... in Vietnam as the Resistance War Against America (Vietnamese: Kháng chiến chống Mỹ) or simply the American War ...
In contrast, the USA were trying to inhibit the spread of communism, i.e., it was an anti-communism war. So communist China entered to support the North Vietnamese.
In Chinese the Vietnam War is called 越南战争 (literally Vietnam [越南] War [战争], the same as in English). I find this historically and etymologically curious: there is the phrase 抗日战争 ("Resistance War Against the Japanese") which could be easily adapted to 抗美战争, but wasn't.
Question: Why isn't the Vietnam War called e.g. 抗美战争 ("Resistance War Against America") like in Vietnamese?