Proxy wars occurred during the cold war in greece, afghanistan, vietnam, and korea. which option below offers the best definition of proxy war?

A proxy war by definition is "A war instigated by a major power but itself does not get involved" I know the U.S got involved in Korea. Vietnam and had to help the British keep control during the Greek civil war so I'd go with Afghanistan since the U.S only supplied insurgent groups with weaponry and did not challenge the USSR openly.