NARUTO, Tokushima Pref. — At 2:30 p.m. on Aug. 23, 1914, despite opposition among many pro-German military officers and politicians, Japan honored a 1902 treaty with Britain and declared war on Imperial Germany.

Earlier that month, Germany and Austria-Hungary declared war on France, Russia and Britain. With Japan's entrance on the side of the Triple Entente, the conflict reached Asia.

Rather than send troops to northern France and Belgium, where the trench war was raging, Japan, with British agreement, decided to attack the German colony at Tsingtao, China, while its Imperial navy seized coaling stations in the Mariana Islands that had been abandoned by the German Pacific Fleet racing to get back to Europe.