A former member of the American intelligence community with a fit of conscience reveals important classified information about signals intelligence intercepts and capabilities, which then causes an international and domestic stir. Yes, this synopsis applies to Edward Snowden and his leak about the National Security Agency's Prism program to The Guardian last week, but it also has some interesting similarities—and dissimilarities to be sure—with another leak from more than 80 years ago.
In 1932, Herbert O. Yardley published "The American Black Chamber." This book revealed sources, methods and operational details for how American cryptographic intelligence personnel had broken all manner of diplomatic codes and ciphers while monitoring international telegraph traffic.
Yardley claimed to be doing this because he wanted the American people to know about what he thought to be their government's unilateral disarmament to the threat of foreign signals intelligence – although others also claimed there was a financial motivation, too. Yardley's Black Chamber bureau was shut down in 1929 on the orders of Secretary of State Henry L. Stimson. Stimson famously quipped: "Gentlemen do not read each other's mail."
The book's publication caused an international stir. It was translated into several languages, including Japanese, and it was in Japan where the book caused the biggest stir of all. As Yardley revealed, in 1921 and 1922 the United States had used the work of the Black Chamber to extract favorable terms in the Limitation of Armament Conference, constraining the Japanese navy's allowable tonnage compared to more advantageous weights allowed for the U.S. and British fleets.
A second book, "Japanese Diplomatic Secrets, 1921-22" was unpublished due to threats from the War and Justice Departments to publishers over its disclosure of classified materials. But the damage was already done. The Japanese and others would use the materials gained to strengthen their cryptographic security, which had deadly consequences for the United States at the beginning of the Second World War.
Fast forward to 2013 and it is unclear at this time what impact Edward Snowden's leak will have on future U.S. national security. Much will likely depend on what he does moving forward.
His selection of Hong Kong as a hiding spot is certainly unusual. The timing of these revelations during President Barack Obama's meeting with Chinese President Xi Jinping was also, at best, curious. Russia's offer of maybe, possibly granting Snowden amnesty, while surely a move to needle the U.S., is also interesting. But Snowden's behavior moving forward will reveal whether this was a fit of social libertarian conscience or something more nefarious.
Regardless, Snowden's revelations must be punished. Whether one thinks that he is right or wrong, he did something illegal. Furthermore, both judicial reviews and legislative oversight said that the programs he divulged were legal. (Of course further judicial review might overturn them, but that is immaterial at the moment.) Hopefully his divulgence won't have the same consequences that Yardley's revelations led to long ago.
Michael P. Noonan is the Director of the Program on National Security at the Foreign Policy Research Institute in Philadelphia, Pennsylvania, and a veteran of Operation Iraqi Freedom.