officially Staatssicherheit ("State Security")
Secret police of East Germany (1950–90), established with Soviet help by German communists in Soviet-occupied Germany after World War II. It was responsible for both domestic political surveillance and espionage.
At its peak, it employed 85,000 officers full-time. Using hundreds of thousands of informers, it monitored one-third of the population. Most of its foreign operations were focused on West Germany
whose governing circles and military and intelligence services it successfully penetrated
and West Germany's NATO allies. The Stasi was disbanded after German reunification. In 1991 the newly reunified German government passed the Stasi Records Law, under which East German citizens and foreigners were granted the right to view their Stasi files. By the early 21st century, more than 1.5 million individuals had done so.