Because of its central geographic position within the Yugoslav federation, post-war Bosnia was strategically selected as a base for the development of the military defense industry.Being one of the poorer republics in the early 1950s it quickly recovered economically, taking advantage of its extensive natural resources to stimulate industrial development.The Yugoslavian communist doctrine of "brotherhood and unity" particularly suited Bosnia's diverse and multi-ethnic society that, because of such an imposed system of tolerance, thrived culturally and socially.While working within the communist system, politicians such as Džemal Bijedić, Branko Mikulić and Hamdija Pozderac reinforced and protected the sovereignty of Bosnia and Herzegovina.The Sarajevo process centered on convicting Alija Izetbegović for writing "The Islamic Declaration", a literary work which was in the Yugoslav communist regime considered a radical approach towards socialist ideals of former Yugoslavia that were based on suppression of nationalism and any violation of that doctrine was punishable by law.[citation needed] With the fall of communism and the start of the break-up of Yugoslavia, the old communist doctrine of tolerance began to lose its strength, creating an opportunity for nationalist elements in the society to spread their influence.The decision of the Parliament of the Socialist Republic of Bosnia and Herzegovina on holding the referendum was taken after the majority of Bosnian Serb members had left the assembly in protest.