American Military History, Volume 2 by Richard W. Stewart

During the summer of 1945 Allied forces in the Pacific had stepped up the pace of their air and naval attacks against Japan. In June and July carrier-based planes of the U.S. Pacific Fleet and U.S. Army Air Forces planes from the Marianas, Iwo Jima, and Okinawa struck the Japanese home islands continuously.

During July Pacific Fleet surface units bom- barded Japan's east coast, and in the same month a British carrier task force joined the attack. Planes from the Philippines hit Japanese shipping in the South China Sea and extended their strikes as far as Formosa and other targets along the South China coast. American submarines redou- bled their efforts to sweep Japanese shipping from the sea and sever the shipping lanes from Japan to the Indies and Southeast Asia. Throughout the war, in fact, submarines had preyed on Japanese merchant and com- bat vessels, playing a major role in isolating Japan from its conquests and thereby drastically reducing Japan's ability to wage war.