Pre-World War II United States Naval Communication Intelligence (COMINT) operations were largely conducted by Navy personnel. However, some 40 USMC officers and enlisted personnel whose contributions have gone relatively unheralded but were no less important were also involved.
Their activities contributed materially to the Navy’s ultimate success against Japanese diplomatic and naval encrypted communications systems, and served as a training ground for those who later founded tactical direct support to Marine forces participating in the amphibious campaigns of World War II.
Shanghai – First Shore Site Established
The Navy’s formal COMINT effort is considered to have begun in January 1924 with the establishment of the Research Desk in the Navy Communications Code and Signal Section (later known as OP-20-G). The Research Desk’s primary mission was, “…to develop cryptographic system for the U.S. Navy which would avoid weaknesses observed in cryptographic techniques employed by foreign government.” This mission required regular acquisition for foreign message traffic but resources were limited. There were few technically proficient intercept operators and no dedicated intercept facilities. Commander in Chief, Asiatic Fleet (CinCAF) was encouraged to expand his Far East radio intelligence capability beyond that on the flagship, USS HURON (CA 9). As a result, the first shore based Navy intercept station (Station “A”) was established in 1924 at the American Consulate, Shanghai targeting Japanese naval communications.
In October 1927, the intercept station was relocated on board the USS GENERAL ALAVA (AG 5), the station ship at Shanghai, where it remained until disestablished in 1929. Marine Corps participation in COMINT operations began in the late 1920’s when, in response to strategic requirements of the Office of Naval Intelligence (ONI) and local requirements of CinCAF, Marine officers trained in the Japanese language and cryptanalysis, and enlisted communications operators cross-trained in Japanese KANA Morse code, were first employed. To expand OP-20-G ‘s cryptanalysis effort, LT Safford recommended establishment of a 16-week officer training course including the basic of code breaking, cipher solution, U.S. Navy cryptographic systems, radio security and radio intelligence. One Marine and four Navy officers comprised the first class (1 Oct 1925 – 31 Jan 1926). Capt Leo F. S. Horan, USMC, attended training at the specific oral request of the Commandant of the Marine Corps (CMC) but was never assigned to COMINT related activities after graduation.
Marines Have History in China
The Marine Corps had a long history of operations in China beginning as early as 1844 with 44 Marines and sailors from the sloop of war USS ST. LOUIS (C 20 / CA 18) landing near Canton to protect Americans from Chinese mobs. Marines also protected American during the Boxer Rebellion of 1900, the Revolution of 1911-1912 and the civil wars of the 1920’s. It was only logical to take advantage of the historical Marines Corps presence in Peiping by establishing an intercept station staffed by Marine KANA-trained communicator to supplement the Navy’s intercept stations on Guam and in the Philippines.
The Radio Security Station was an integral part of Radio Station, Marine Detachment, American Legation, Peiping, China, which served all U.S. government activities in the Chinese capital and was part of the U.S. Asiatic Fleet’s communication network. Radio Station Peiping was operated by Marine general service communicators who were also assigned to COMINT intercept operations. Its mission was to obtain intercept material for OP-20-G’s cryptanalytic activities and provide intelligence to CinCAF. Its primary target was Japanese naval low frequency (LF) and intermediate frequency (IF) circuits.
One Navy general service communicator, CRM Dorman A. Chauncey who reported for duty on October 23, 1927, was assigned under a “cover” assignment as “Assistant to the Radio Station OIC.” Unlike his Marine counterparts, his actual duties were devoted solely to COMINT. The Peiping intercept site itself was both unremarkable and quite primitive. Across what is describe as a “not very high wall” was a public thoroughfare which also served as a boundary between the American and French sectors. When warm summer evening required the station’s windows be opened for ventilation, intercept operators had to keep the receivers volume low. Otherwise passerby on the thoroughfare could have heard the intercepted signals, particularly those originator from the Japanese Embassy only five blocks away.
By James McIntire and R. D. Howell, Sr. (NCVA)
Edited by Mario Vulcano