What four letters acronym stand for kgb in 1920s?

The four-letter acronym that stands for KGB in the 1920s is "GPU," which stands for "State Political Directorate" (Государственное политическое управление) in Russian. The GPU was a predecessor of the KGB and operated as the main security agency in the Soviet Union during that period. It was responsible for political surveillance, suppression of dissent, and intelligence activities. The KGB was officially established later, in 1954, evolving from earlier organizations like the GPU.