W
I drew this black line on this map. Its a very rough line of where the border between the USA's empire and China's empire meet in this area of the world. The frontlines can shift back and forth all down the line.
The big picture view is as long as the fighting is there, its not in the USA or China. Say the West was threatening to break into Russia itself, then China could massively increasing support to Russia. Including outright the Chinese army coming in. But say the frontlines are moving back and forth in Ukraine, then China can support Russia enough that the war is even.
Its like in the Vietnam war. If the US military was tied down fighting in South Vietnam.. and China and the Soviet Union were heavily supporting North Vietnam, it means that is where the fighting is. Which wasn't that consequential to the big powers whatever happened in Vietnam. Yet they got to test out weapons systems, got to test out military tactics and strategy.
