Why Yugoslavia not a nation state?

The 1948 Yugoslavia-Soviet split

Explanation:

All the Communist European Countries had deferred to Stalin and rejected the Marshall Plan aid in 1947. However, in 1948 Tito broke decisively with Stalin on other issues, making Yugoslavia an independent communist state.

Government: Monarchy (1918-1941); Socialist

Official languages: Serbo-Croatian; Macedoni

Historical era: 20th century