German East Africa stood strong against British attempts to capture the territory. The key to capturing the German colony was to contest German control of Lake Tanganyika.

Political instability and mounting foreign debts lead to US military intervention on the island of Hispaniola.

By the summer of 1915, both the Central Powers and the Allies were keen to get Bulgaria to join the war on their side. The Central Powers won the bidding war, and Bulgaria became the fourth (and last) member of the Central Powers.