By the summer of 1944, America increasingly controlled the seas and skies of the Pacific, but the fighting on land remained bloody and brutal. As U.S. forces battled for two islands at once, Japan used ingenious dug-in bunkers and caves to make them pay for every inch of ground. Discover America's strategic and personal motivations behind their simultaneous invasions of Tinian and Guam and witness their far less successful plan to strike Japan from India and China with the new, troubled aircraft, the B-29.

• Jeff Wilburn