During World War I, the two main alliances were the Allies and the Central Powers.
-
Allies: This coalition primarily included France, the United Kingdom, Russia, Italy (which joined in 1915), and the United States (which joined in 1917). Other countries also supported the Allies.
-
Central Powers: This alliance consisted mainly of Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria.
These alliances were a key factor in the escalation of the conflict, as they involved numerous countries and their respective military forces.