British and American ability to read Axis radio communications during World War II was an important contribution to Allied victory in 1945. Cryptological breakthroughs like ULTRA and MAGIC undeniably were impressive and significant, but most of the information that the US Army had about the armed forces of the Axis powers before December 1941 came from the routine, tedious, and often unappreciated peacetime collection efforts of US Army military attaches.
Attaches were the Army’s eyes and ears abroad in the days before satellite photography and sophisticated electronic intelligence collection techniques. They were not spies. They used overt means and sources to collect facts about foreign weapons specifications, military doctrine, and order of battle.