Why was the Vietnam War considered a "battlefield of the Cold War"?

The war ended with an agreement between the U.S. and the Union of Soviet Socialist Republics.
Soviet troops fought U.S. troops throughout the Vietnam War.
The Vietnam War resulted in the containment of communism.
The Soviet Union and China provided military aid to Vietnam.

The Vietnam War was considered a "battlefield of the Cold War" because it was a proxy war between the United States (backed by Western allies) and the Soviet Union and China (backing North Vietnam). It was seen as a battle between capitalism and communism, with each side trying to expand their influence and ideology. The involvement of major world powers and their support for opposing sides made Vietnam a key battleground in the larger ideological conflict of the Cold War.