Often forgotten among the many aspects of World War II is the alliance between Germany and Japan. Because of the vast geographical separation between these two Axis nations, and because of some of very real philosophical and operational differences, the alliance was fraught with difficulty. But in the vast middle-ground of the Indian Ocean, these "reluctant allies" did come together to conduct naval operations that might well have had disastrous consequences for the Allies but for the intervention of fate and the inevitable friction of war. Captain Krug served in U-boats in that theater and in the Far East and, with the assistance of scholars of both nations, he has produced a very readable and meticulously researched account of German and Japanese naval interaction. Besides thoroughly covering—for the first time—this neglected topic, the authors provide valuable insight into the faulty mechanism of an alliance between totalitarian powers, characterized by suspicion and a reluctance to freely share information and assets. They also bring to light the difficulties—and ultimate consequences—of dealing with the megalomania and criminal intellect of Adolf Hitler, which resulted in war-crime trials for some of the participants. Proving that not every aspect of the world's greatest war has been covered, this book is a valuable contribution to the ever-expanding lore of the war and will be required reading for those with an interest in naval operations, global strategy, and international diplomacy during the period.