This might have been possible if you can work out a POD where Governor Al Smith wins the 1932 election instead of Vice President William Borah, who won almost every state in OTL's 1932 election. Even if it's unlikely, Smith was famously enthusiastic about the USA needing to get involved in the European Liberation War, speaking out against the Nazis earlier than most, so he could probably make the United States into a power capable of opposing the Soviet Union earlier. Hell, if he ends American neutrality, Capitalist powers might have stood a chance against the Fascists and might have even avoided occupation entirely by crushing them before they could build up militaries. That said, the breakup of Yugoslavia into multiple states was almost inevitable, it was only a matter of time until the Serbs and Croatians were pitted against each other by some foreign power.