Arguably the greatest spy for the West during the Cold War, Dimitri Polyakov was a Soviet Major General in the GRU who revealed Soviet secrets to the FBI and CIA for nearly 25 years. Polyakov provided intelligence on China and Soviet-era weapons capability and was credited with keeping the Cold War from getting hot.

Vladimir Vetrov was a KGB Line X (technical espionage) officer who worked for the French intelligence service. The Soviet technical and economic espionage material he provided to the French was called the “Farewell Dossier,” and was shared by French President Mitterand with U.S. President Ronald Reagan. He was ultimately betrayed by his own wrong-doing.

Working as an interpreter at the U.S. embassy in Bonn, Gabrielle Kleim was recruited by an East German Intelligence officer posing as a love interest. She was among several West German secretaries recruited by East German so-called “Romeo Spies” working at the behest of the “Man Without a Face,” East German HVA Intel Chief Marcus Wolf.

While a prisoner in North Korea, George Blake was recruited by the Soviets to spy on the British. Blake caused tremendous damage to MI6 and its allies around the world and was ultimately convicted and sentenced to 42 years in prison. He would later escape in an audacious prison break and find refuge in the Soviet Union.

Apple Inc. and Tesla’s autonomous vehicle programs are two of the many high profile companies being targeted by Chinese trade theft. Xialong Zhang, an engineer, with access to Apple’s project code and Cao Guangzhi, an electrical engineer with Tesla are both caught trying to steal secrets on autonomous driving vehicles for a Chinese competitor..

Referred to as the GRU, the Glavnoe Razvedyvatelnoe Upravlenie was created in 1918 and served as the Soviet Union's chief military intelligence group.

In a series focusing on 20th-century espionage, we focus on the Komitet Gosudarstvennoe Bezopasnosti (Committee for State Security), the agency of the former Soviet Union responsible for state security from 1954 to 1991.

A look at America's Office of Strategic Services, which was modeled on the British Special Operations Executive.