During World War 1 Japan came to the British's aid in the Mediterranean.
Before 1914, Britain's sole official alliance was with Japan, and it was intended to relieve the Royal Navy of some of the responsibility of protecting Britain's Asian colonies, as well as to allow Britain and Japan to assist each other in safeguarding their respective interests in China and Korea. When the war broke out, the Japanese targeted German colonies in the Pacific and China, but Britain asked Japan for help with escort duties in the Mediterranean in 1917. The region was critical for feeding Allied soldiers in Italy and Greece, as well as maintaining contacts with Africa, but German and Austrian submarines posed a threat to Allied fleets. The Japanese, operating out of Malta, supplied escorts for Allied com