The cause of the war came from Bulgaria, as they were dissatisfied with the territory from the previous conflict, leading them to attack Serbia and Greece to claim more land in the Macedonian region. Despite their initial attack, Bulgaria suffered immense losses, as it was outnumbered by the Romanians and Ottomans. Although the war was less than three months, Bulgaria suffered significant military and territorial losses, forcing it to surrender. Serbia and Greece took control of their Macedonian land, Romania now controlled Southern Dobruja, and the Ottoman Empire regained part of its land in Eastern Thrace. With new control amongst those countries, the Treaty of Bucharest was signed in August 1913 to finalize the updated borders. The Second Balkan War influenced World War I due to deepened rivalries within the region. For example, when Serbia gained land from the Austro-Hungarian Empire, that came as a surprise to the latter. These constant territorial conflicts and instability led to chaos in the Balkans, eventually developing into World War I.