Lably
Skip to content

Project SHAMROCK

Cold-War era US espionage exercise

  • 3 min read
  • 2 chapters

Explore on Lably

ToursExplore Lably’s 3D tours

Operations

According to military historian Stephen Budiansky, the precursor to the project occurred in 1940: "In January 1940 the Army's adjutant general sent a letter to the president of RCA, David Sarnoff, asking if a Lieutenant Earle F. Cook might be assigned to the company..." Cook photographed all international commercial cablegrams. "The clandestine arrangement—almost certainly illegal—set a precedent..." Official wartime censorship began in Dec. 1940, when all cables were "turned over to the government for inspection." According to Louis W. Tordella, "the collection program 'just ran on' ever since its beginning in World War II 'without a great deal of attention from anyone'..." Three major cable companies provided copies of all international telegrams passing through New York, Washington, and San Francisco. In the 1950s, "New Shamrock" tapped the links of 60–70 foreign embassies.

According to FBI historian Athan Theoharis, the post-World War II continuation of Project SHAMROCK brought hesitation from the telegraph companies, who were concerned about the legality of their actions and that employees would reveal the companies' government cooperation to the public. Their fears were assuaged after a promise from Attorney General Tom Clark that the U.S. government would not prosecute the companies for their participation in Project SHAMROCK, and after Congress approved a bill section that made it illegal for "unauthorized" individuals to reveal information related to code-breaking, which was a part of SHAMROCK's operations.

At the height of Project SHAMROCK, 150,000 messages were printed and analyzed by NSA personnel in a month.

Sign in to keep reading

One more chapter is free with a Lably account.

More in Computing and communication