Operation Shamrock

Operation Shamrock


Operation Shamrock was a covert, domestic intelligence gathering operation that monitored telegraph communications. Shamrock began as a military intelligence program during World War II, but continued until the 1970s. The operation sparked controversy when details of Shamrock were leaked to the public after a government investigation in 1975. The government investigative committee claimed that Shamrock intended to monitor only messages that posed a threat to national security, but that it had free access to all wire traffic.

At its outset, Shamrock was a World War II military intelligence program. In the months before war broke out in Europe in 1939, the Army Signal Security Agency asked the three largest wire service companies, ITT World Communications, Western Union International, and RCA Global, for permission to tap their international cables to eavesdrop on foreign coded transmissions. The companies agreed, and Army Intelligence intercepted coded messages. Later, intelligence agents began to intercept all civilian and military wire traffic, both ciphered and plain-text.

Telegraph messages between the frontline and the home front were monitored and censored for sensitive content, such as troop locations and strategic battle plans. Military intelligence agents also sought to root out espionage communications and kept intercepts between political groups and other organizations with Axis sympathies. Thus, Shamrock was initially a wartime censorship program to cull sensitive information from the public domain in the interest of national security.

Shamrock continued, however, for nearly three decades after the end of World War II. At the war's end, Army Intelligence appealed to the major communications companies to continue their monitoring of international wire traffic. Their request was granted. When President Harry S. Truman created the National Security Agency (NSA) in 1952, the agency immediately took control of the ongoing telegraph communications monitoring. The program then acquired the code name Operation Shamrock. NSA authorities continued to monitor incoming and outgoing wire traffic from the monitoring station in New York. However, the transport of voluminous telegraph recording tape became difficult to transport. Technological advancements permitted the recording of the data on magnetic tapes, and to centralize the operation, the NSA created a New York office devoted to Shamrock. The office continued to operate until the mid 1970s, but the nature of monitoring and recording information changed significantly since the program's inception.

After World War II, the focus of Shamrock shifted to follow Cold War policies. Shamrock sought to identify and monitor Soviet sympathizers, radical political organizations, international espionage agencies, and other perceived security threats. When the Vietnam conflict was at its height, Shamrock operatives kept lists of anti-war organizations and monitored communications of some individuals who fled the draft. These lists were code named Minaret, and by 1974 contained information on nearly 70,000 American citizens.

In 1975, the Senate Select Committee to Study Governmental Operations with Respect to Intelligence Activities, otherwise known as the Church Committee after its chairman, Senator Frank Church, conducted a comprehensive investigation of the U.S. intelligence agencies after the Watergate scandal. The Church Committee report concluded that Army intelligence and the NSA did have free access to wire traffic, and did compile information on private citizens. The committee further concluded that Shamrock did not continue past 1974, and that no further action or investigation of the matter was necessary.



United States National Security Agency. < http://www.nsa.gov > (03 January 2003).


Church Committee

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