From the Battle of the Atlantic and the land war in Europe and Africa to the Pacific Theater operations, intelligence operations played major roles in battles throughout WWII. German U-boats seemed to have the upper hand in the Atlantic until the allies broke the military codes being used. The spies and saboteurs operating throughout Europe provided vital intelligence at great risk. Japanese codes were broken which provided Admiral Nimitz and other leaders the advantages they needed to turn back the advancing Japanese forces. These presentations highlight the intelligence operations that made the difference in the Allies winning this truly worldwide war.