Operation ‘Piet’: The Joseph Sidney Petersen Jr. Spy Case, a Dutch ‘Mole’ Inside the National Security Agency

Abstract

In 1986 it was discovered that Jonathan Jay Pollard, an employee of US Naval Intelligence, had worked as a spy for Israel. Until then the case of Joseph Sidney Petersen was the most important example of espionage against an US intelligence service by an ally. Petersen, who worked for the National Security Agency, was arrested in October 1954 and charged with obtaining top secret documents to the injury of the United States or to the advantage of a foreign nation. According to the International Herald Tribune this represented a case with worldwide implications. During the subsequent trial it emerged that Petersen had forwarded these top secret codeword documents to the Netherlands. For the first time an attempt will be made here to fully reconstruct the Petersen affair based on declassified American and Dutch archival holdings. Special attention will be paid to when Petersen was recruited and by whom, how long his spying lasted, what intelligence he delivered to the Dutch, what led to his arrest and trial and what the impact that had on American–Dutch relations. This article will close with some still remaining and unanswered questions.