Yeah, after the '48 split there was little love between the USSR and SFRY, at least until Stalin died.

Time for an official sheet:

Nation's full name: Socialist Federal Republic of Yugoslavia
Population: ~16-16.5 million (based on the 1948 (15.8 mil.) and 1953 (16.9 mil) censuses.
Current leader's name: Josip Broz Tito
Allegiance: Neutral
Military strength: 600,000-800,000 active, unknown reserve (top was over 3 million in '90) but was probably around 1-2 million troops at this time.