Naval intelligence is an aspect of World War II that has received scant attention. Now former naval intelligence officer Alan Harris Bath traces the coordination of Anglo-American efforts before and during the war, identifying the political, military, technological, and human factors that aided and sometimes hindered cooperation. He compares the Allies' different and often conflicting styles of intelligence gathering and reveals ways in which interagency and interservice rivalries complicated an already complex process. Drawing on archives in the United States, United Kingdom, and British Commonwealth, Bath describes how cooperation took place at all levels of decision-making, in all theaters of war, and at all points in the intelligence cycle, from gathering through analysis to dissemination. He tells how the United States learned from Britain's longer experience with the war and how intelligence cooperation was always subordinated to, and in the final months of war impeded by, Anglo-American political relations.