OSS

The OSS was an American intelligence agency, that functioned for several years during World War II.

When the United States entered World War 2, its ally, the United Kingdom, had been at war for over two years. Unlike the USA the UK had an intelligence agency with a mandate to conduct operations in foreign countries -- MI6. Prime Minister Winston Churchill had created new additional intelligence agencies, including the Special Operations Executive (SOE).

OSS was modeled after the UK's SOE. Both agencies recruited ex-patriates of occupied Europe, gave them a crash course in espionage, and then placed them back in Europe, where their tasks including sabotaging the German occupiers infrastructure, or aiding elements of underground resistance groups to engage in sabotage. Technically, these war-like acts, carried out by individuals in civilian clothes, were violations of the Geneva Conventions -- ie warcrimes.

Most of these poorly trained agents were quickly detected by German counter-intelligence.