In 1992, the discovery in the Soviet archives of the NKVD’s secret operational orders has drastically changed our perception of Stalin’s Great Terror. These documents disclosed the mechanisms of the hitherto hidden side of the Great Terror – that of the mass secret repressive operations (as opposed to the "public side" – that of the "show trials" and the purges of the political, economic and military elites). These secret operations were a form of social engineering intended to rid the country "once and for all of the entire gang of anti-Soviet elements who undermine the foundations of the Soviet State" (in the words of Nikolai Ezhov, the Head of the NKVD, in the preamble of Order n° 00447). Two main groups of "enemies" were targeted:
The Kulak Operation, launched by the NKVD Operational Order n° 00447 dated July 30, 1937, targeted a wide category of previously identified "social outcasts": the innumerable cohort of "formers", directly and purposefully marginalized in the 1930s ("former kulaks", "former members of anti-Soviet parties", "former White officers", "former tsarist civil servants" and "church officials"), but also various kinds of "socially harmful elements" (such as "recidivist criminals", "bandits", "hooligans", "speculators", "persons with no definite place of work or having ties with the criminal world", etc).
The "National Operations" targeted a number of diaspora minorities, suspected of being "a hotbed of spies and wreckers". On July 25, 1937, Nikolai Ezhov sent to all regional NKVD headquarters Order n° 00439 prescribing the immediate arrest of all German citizens employed (or having been employed) in defense factories, on the railroads and in "other sectors of the national economy". But "Germans" were not the main target: Order n° 00449 prescribed the arrest of all Soviet citizens "having, or having had, ties", in one way or another, with "German spies, wreckers and terrorists". This, of course, considerably widened the scope of the operation, since no more than 4,000 German citizens were registered in the Soviet Union in 1937 (Okhotin & Roginskii, 1999).
Two weeks later, on August 11, 1937, following a Politburo top-secret resolution taken two days earlier, Nikolai Ezhov issued another secret directive, Order n° 00485, aimed at "the complete liquidation of local branches of the Polish Military Organization (POW) and its networks of spies, wreckers and terrorists in industry, transport and agriculture". Order n° 00485 identified targets for arrest: all Polish political émigrés and refugees, as well as "the most active part of local anti-Soviet nationalist elements from the Polish national districts". A month later, this category was extended to all "Soviet citizens of Polish nationality with ties to Polish consulates", a category that could easily embrace any Soviet Pole.
Order n° 00485 served as a model for a series of similar NKVD secret decrees targeting a number of the Soviet Union’s diaspora nationalities: the Finnish, Latvian, Estonian, Rumanian, Greek, and Chinese. The NKVD referred to these decrees collectively as "the National Operations" directed against "nationalities of foreign governments". Concerning diaspora minorities, the vast majority of whom were Soviet citizens and whose ancestors had resided for decades and sometimes centuries in the Soviet Union and Russian Empire, "this designation absolutized their cross-border ethnicities as the only salient aspect of their identity, sufficient proof of their disloyalty and sufficient justification for their arrest and execution" (Martin, 2001: 338). Oleg Khlevniuk has convinsingly shown, on the basis of Stalin’s correspondence with Soviet diplomats and NKVD officials in Spain in the months preceding the Great Terror, that the launching of the National Operations was related to Stalin’s reading of rearguard uprisings against the Republican regime in Spain in the course of the Spanish Civil War. Stalin was convinced that hostile capitalist powers such as Germany, Poland, Japan, Finland, Romania and the Baltic States would organize, in the ever more probable event of war with the Soviet Union, the same kind of rearguard uprisings, resorting to anyone who had some sort of connection with foreign countries, in order to form a "fifth column of diversionists and wreckers" (Khlevniuk, 2000).