Japan.
Well obviously,its a civil war, so it was between china and china, so china. To answer your question
to support U.S. trade goals by helping to preserve China as a nation.
united nations forces fought against comunist north Korea and soldiers from communist china
china
it is japan
Japan
The country was Japan, which is actually several islands.
China
they fought against the axis powers in WWII and they fought against America in the Vietnam War
Japan
China
they fought against Germany
Japan
There is Taiwan island, a bit higher than 23N latitude, but now it is not a nation. Taiwan is territory of China.
The Korean War 1950-1953, against Red China. Nationalist China (Taiwan) was an ally with the US.
JAPAN