The Kingdom of Bulgaria participated in World War I on the side of the Central Powers between 15 October 1915, when the country declared war on Serbia, and 29 September 1918, when the Armistice of Thessalonica was signed. In the aftermath of the Balkan Wars, Bulgarian opinion turned against Russia and the western powers, whom the Bulgarians felt had done nothing to help them. The government of Vasil Radoslavov aligned the country with Germany and Austria-Hungary, even though this meant also becoming an ally of the Ottomans, Bulgaria's traditional enemy. However, Bulgaria now had no claims against the Ottomans, whereas Serbia, Greece and Romania (allies of Britain and France) were all in possession of lands perceived in Bulgaria as its own.