It was ordered by the Politburo of the Communist Party against so-called "Polish spies" and customarily interpreted by NKVD officials as relating to 'absolutely all Poles'.

[8] The NKVD agents looked through local phone books to expedite the procedure and detained people with names that sounded Polish.

[7] It was distributed to the local subdivisions of the NKVD simultaneously with Yezhov's thirty-page "secret letter", explaining what the "Polish operation" was all about.

The letter from Yezhov was titled, "On fascist-resurrectionist, spying, diversional, defeationist, and terrorist activity of Polish intelligence in the USSR".

Destroy it in the interest of the USSR.."[14] The "Order" adopted the simplified so-called "album procedure" (as it was called in NKVD circles).

[16] The "Polish Operation" was a second in a series of national operations of the NKVD, carried out by the Soviet Union against ethnic groups including Latvian, Finnish, German, and Romanian, based on a theory about an internal enemy (i.e., the fifth column), labelled as the "hostile capitalist surrounding" residing along its western borders.

[2] In the opinion of historian Timothy Snyder, this fabricated justification was intended only to cover-up the state-sanctioned campaign of mass-murder aiming to eradicate Poles as a national (and linguistic) minority group.

Meanwhile, the Communist International helped by revisiting its files in search of Polish members, producing another bountiful source of made-up evidence.

[18] The largest group of people with a Polish background, around 40 percent of all victims, came from Soviet Ukraine, especially from the districts near the border with Poland.

Statistical extrapolation, wrote Jasiński, increases the number of Polish victims in 1937–1938 to around 200–250,000 depending on the size of their families.

As more than 100,000 innocent people were killed on the spurious grounds that theirs was a disloyal ethnicity, Stalin spoke of "Polish filth".

[30][better source needed] On the other hand, Stalin often praised Poland as a good nation and the Poles as brave fighters, the third most "dogged" soldiers after the Russians and Germans.

[33] According to historians Olle Sundström and Andrej Kotljarchuk, most scholars (for example, Nicolas Werth, Michael Mann and Hiroaki Kuromiya) focus on the security dilemma in the border areas suggesting the need to secure the ethnic integrity of Soviet space vis-à-vis neighboring capitalistic enemy states.