A unique kind of challenge to communist rule occurred in Yugoslavia, starting with political reforms in the late 1980s in the republics of Slovenia and Croatia, where Communist Party leaders had always been somewhat more liberal than those in other Yugoslav republics. Before long, newly elected nationalist- inspired governments in Slovenia and Croatia separated from the Yugoslav state. The independence of Slovenia and Croatia, which helped trigger the independence of Bosnia-Herzegovina and Macedonia, precipitated the disintegration of the Titoist state. It also contributed to the outbreak of war in the newly independent republic of Croatia and Bosnia-Herzegovina as the different ethnic groups, now freed of communist control, indulged their historic prejudices and began a campaign of landgrabbing. The most aggressive of these groups turned out to be the Serb minorities who were encouraged by the Serb Republic government of President Slobodan Milošević.
Communist system had been ripe for revolt for many years, with flaws that rendered them inept and hypocritical and deprived them of the popular legitimacy needed to assure their long-term survival. They collapsed in 1989, rather than earlier or later, largely because of the Soviet Union, which under Gorbachev encouraged reform to correct these flaws but then refused to defend them against popular demands for more change and eventually for the complete abandonment of communism and satellization. And, although the West was a catalyst, not a cause, of the collapse of communist systems in Eastern Europe, its role should not be underestimated. Western countries, in particular the United States, had been trying to weaken the East European communist political systems internally and externally for several decades. The West also had succeeded in lulling the Kremlin into a sense of security that helped to encourage a more flexible Soviet approach to the region and eventually to allow change to run its natural course. Moreover, the longer the Kremlin remained passive, the more difficult it became to reverse that behavior--and the West helped to make sure of that.
While the causes of collapse were rather similar throughout the region, the actual process of communist collapse varied from country to country depending on the differences, however subtle from an outsider's point of view, in how the communist system actually worked in each country. In the more highly developed north, namely, in Poland, Hungary, and Czechoslovakia, there were people even within the Communist Party with strong liberal instincts ready to lead a radical and profound shift away from orthodox communist rule. In the Balkans, however, which were less developed politically and economically and lacked the kind of liberal elite found in the northern countries, the collapse was more traumatic and more violent.