Secret service World War, 1939-1945 50 History 24 Spies 10 Biography 9 Military intelligence 9 Cryptography 7 Espionage 5 World war, 1939-1945 5 Politics and government 4 Underground movements 4 Campaigns 3 Great Britain 3 Personal narratives, British 3 United States 3 Deception 2 Espionage, Germany 2 Germany 2 Personal narratives, American 2 World War 2 World war 2 Afghan War, 2001- 1 Anecdotes 1 Campaigns, 1 Central Intelligence Agency 1 Civil War, 1861-1865 1 Cold War 1 Commando troops 1 Espionage, British 1 Espionage, German 1