When the Kingdom of Yugoslavia was occupied by Nazi forces during World War II, Bosnia was ceded to the Nazi-puppet state of Croatia. Nazi rule in Bosnia led to much persecution, and the Jewish population was nearly exterminated. Many Serbs took up arms and joined the Chetniks, the Serb royalist-nationalist resistance movement. However, the movement against the Nazis also caused many problems for the Bosnian Muslims, and as a consequence, several Bosnian Muslim parliamentary units joined the Axis powers.

In the beginning of 1941, Yugoslav communists, under the rule of Josip Broz Tito, organised the ‘partisons’, a multi-ethnic resistance group who fought against the Chetnik and Axis forces. In 1943, Tito’s Anti-Fascist Council of the National Liberation of Yugoslavia held a conference in Jajce which re-established Bosnia and Herzegovina as a republic of the Yugoslavian federation. The Allies supported the partisans, and at the end of the war, the Socialist Federal Republic of Yugoslavia was established. Its constitution from 1946 officially declared Bosnia and Herzegovina as one of the six constituent republics within the new state, and Tito became president of the country.

In 1948, Bosnia and Herzegovina was granted the status of a republic. Tito followed the Soviet Union’s pattern of nationalising businesses and industry, but simultaneously managed to keep the autonomy of the country. Tito’s iron-hand dictatorship kept ethnic hostility and regional conflicts between Bosnia-Herzegovina, Serbia, Slovenia, Croatia, Macedonia and Montenegro in check. Tito died in 1980 and his government was replaced by Communism, with members of the state presidency represented by each of the six republics and two provinces. This system led to growing political instability and economic difficulties, as also seen in other such crumbling regimes of Eastern European countries.