Triplex (espionage)

{{Short description|British World War II intelligence program that opened neutral diplomatic pouches}}

{{Use dmy dates|date=

April 2022}}

Triplex or XXX was the code name of a British espionage operation in World War II{{cite book |author1=Nigel West |url=https://books.google.com/books?id=QrEquyIyQh0C |title=Triplex: Secrets from the Cambridge Spies |author2=Oleg Tsarev |date=22 September 2009 |publisher=Yale University Press |isbn=978-0-300-15641-6 |pages=1}} which involved secretly copying the contents of diplomatic pouches of neutral countries. It is still highly classified in Britain, and the only documents from it are in Moscow, where they were sent by Anthony Blunt, who was a supervisor of the Triplex operation while working for MI5.

Due to travel security restrictions to and from Britain during some periods of the war, the government was able to forbid the use of the embassies' own couriers to transport pouches or was able to separate the courier from the pouch to "censor" the passenger.{{Cite book |last=West |first=Nigel |title=Triplex: Secrets from the Cambridge Spies |last2=Tsarev |first2=Oleg |publisher=Yale University Press |year=2009 |isbn=978-0-300-12347-0 |location=New Haven & London |pages=20}} This provided opportunities to access the pouch and copy the contents for later analysis.