What countries were involved with crisis in the Balkans that started World War 1?

The crisis in the Balkans that contributed to the outbreak of World War I primarily involved Serbia, Austria-Hungary, and the Ottoman Empire. The assassination of Archduke Franz Ferdinand of Austria by a Bosnian Serb nationalist in June 1914 escalated tensions between Serbia and Austria-Hungary. This event triggered a complex web of alliances and conflicts, drawing in other nations like Russia, which supported Serbia, and Germany, which backed Austria-Hungary. Ultimately, these intertwined national interests and rivalries set the stage for the wider conflict of World War I.