U.S. interest in the Far East dates from the earliest years of the republic, when American merchant ships sailed across the vast Pacific to ply their trade in the ports of China, the Philippines, Indochina, and the East Indies. Warships of the U.S. Navy followed soon afterward to protect those commercial carriers and to promote American diplomatic interests in Asia. The U.S. Seventh Fleet, successor to the Asiatic Squadron and Asiatic Fleet of the 19th and early 20th centuries, began making its own naval history in the early days of World War II. Unique among the nation's naval forces, the fleet has taken part in all the major conflicts and most of the crises and confrontations of the last six decades. It has defended U.S. interests and worked with America's Asian alliances to deter aggressors and maintain peace and stability in the region. The fleet's Sailors have provided humanitarian assistance and disaster relief to numerous countries devastated by natural and manmade disasters. The fleet's area of responsibility in the 21st century encompasses 48 million square miles of the Pacific and Indian oceans, an area holding half of the world's population, 35 nations, and many of its most prosperous economies. Much of the world's energy resources and oceangoing trade passes through waters guarded by the warships, aircraft, and men and women of the U.S. Seventh Fleet, whose motto is appropriately-Ready Power for Peace.