NKVD stands for the People's Commissariat of Internal Affairs of the USSR, to which the Soviet secret political police was subordinated from 1934. The NKVD was, in essence, an authority in the Soviet state, at the central level, which continued the bloody traditions of the Cheka and the OGPU. The heads of the NKVD (starting in 1934) were, in turn, Genrich Yagoda, Nikolai Yezhovo and Lavrenty Beria, who was also the last head of this criminal institution. The main tasks of the NKVD included fighting real and imaginary opponents of the communist regime inside the USSR, intimidating Soviet society, as well as implementing the so-called The purge of 1934-1940. It was also the NKVD who most often provided people to perform the functions of political officers in the Red Army. It should also be remembered that in the course of World War II there were also separate NKVD units (often in the strength of divisions!), Which were responsible, for example, for the deportation of people from the given areas or played the role (especially in the period 1941-1943) of the role of barrage troops which were to prevent a possible retreat of the Red Army. Moreover, until 1943, Siersz, i.e. military counterintelligence, dealing with breaking up espionage networks operating in the USSR and areas occupied by the Red Army, existed in the NKVD.
In the 1920s and - especially - in the 1930s, the Red Army underwent a rapid development in terms of increasing its posts, as well as increasing saturation with technical weapons, primarily armored weapons. Still, the infantry was the primary and numerically largest element of the Red Army. The intensive quantitative development of this type of weapon began at the turn of 1929/1930. In 1939, even before the aggression against Poland, the Soviet infantry was formed into 173 divisions (so-called rifle divisions), most of which were grouped in 43 corps. It is worth adding that after the September campaign in 1939, this number increased even more. The Soviet rifle division in 1941 consisted of three rifle regiments (three battalions each), an artillery regiment, after an anti-tank and anti-aircraft artillery division, as well as reconnaissance and communication battalions. In total, it numbered about 14,500 people. However, by 1945 this position underwent significant changes, leading to a division of approximately 11,500-12,000 people, consisting of three infantry regiments, an artillery brigade consisting of three regiments, a self-propelled artillery squadron and many support units, including anti-tank, anti-aircraft weapons or communications. The saturation of infantry units with machine weapons has also increased significantly - for example with the submachine guns APsZ 41, and later APsZ 43.