Intelligence and Cryptanalytic Activities of the Japanese During World War II, Volume 1

This is the published edition of a 1945 U.S. Army intelligence study. It was declassified decades later and issued commercially as the first of a multi-volume Aegean Park Press set. The set documents how Japan's intelligence services were organized and how well, or badly, they read Allied communications during the Second World War.

The report was compiled by the Military Intelligence Service of the War Department General Staff, known as MIS/WDGS. It was later declassified by the National Security Agency under its Special Research History series, as SRH-254. This first volume, subtitled The Japanese Intelligence System, MIS/WDGS, covers the organization and operating methods of Japan's wartime intelligence apparatus. A companion volume in the set addresses Japanese cryptanalytic activity specifically.

Aegean Park Press, a Laguna Hills, California publisher that specialized in reprinting declassified cryptologic and intelligence material, issued the volume in 1986. Authorship is credited to J.W. Bennett, W.A. Hobart, and J.B. Spitzer, the U.S. Army officers who compiled the original 1945 study.