Croatia went through a difficult time from a one-party Yugoslav Republic to a multi-party independent state with its complete territories. The first multi-party democratic elections in Croatia ended peacefully and correctly. Previous events, primarily the dissolution of the League of Communists, determined future events because the strongest party became the Yugoslav National’s Army. The Yugoslav National's Army was supposed to defend all the peoples, but it became a force which was defending the interests of the Serbian rebels in Croatia. August 1991 was the most crucial month as that’s when the Serbian-Yugoslav aggression against Croatia began. Bloody and fierce clashes followed. At the beginning, the Yugoslav National’s Army and Serbian rebels advanced rapidly with the intention of dividing Croatia, i.e. establishing the Virovitica-Karlovac-Karlobag line. However; towards the end of 1991, Croatia managed to form its army with the purpose of defending territorial integrity. In early 1992, a truce was achieved which lasted until 1993, until the beginning of military operations which were launched to liberate occupied territories. The last two military operations are of great importance: Operation Flash and Operation Storm because most of the previously-occupied territories were liberated in a couple of days. The whole process ended with the Serbian-Croatian agreement which was intended to cease hostilities and peacefully return the Danube region to the constitutional order of Croatia.