measures in the East in 1941. This discrepancy wouldn't be sufficiently explained by the German treatment of local people, nor by the quick German advance in 1941, nor by the social circumstances then existing in these regions. There is strong evidence, that this was decision of the central Soviet authorities, who abstained from the greater buildup of the Partisan forces in West Belarus, and let Polish underground military structures to grow unopposed in these lands in 1941–1942, in the context of relations with the Polish government in exile of Sikorsky. Certain level of military cooperation, imposed by the respective commands, was noted between Soviet partisans and the Home Army; the people of Polish nationality were, to a degree, exempted from the terror campaign in 1942. After the break of diplomatic relations between USSR and Polish government in exile in April 1943, the situation changed radically. From this moment on, AK was treated as hostile military force. The build-up of the Soviet partisan force in the Western Belarus was ordered and implemented during 1943, with 9 brigades, 10 detachments and 15 operational groups transferred from the Eastern to Western lands, effectively tripling the Partisan force there (to 36.8 thousand in December 1943). It is estimated that c. 10–12 thousand personnel were transferred, and about same number came from the local volunteers. The build-up of the military force was complemented by the ensuing build-up of the underground Communist Party structures and propaganda activity. Soviet victory at the Battle of Stalingrad, certain curbing of the terror campaign (actually since December 1942, formally in February 1943) and amnesty promised to repenting collaborators were a significant factors in the 1943 growth of the Soviet partisan forces. Desertions from the ranks of the German-controlled Hilfspolizei and military formations strengthened, with sometimes whole units coming over to Soviet partisan side – Volga Tartars battalion (900 personnel, February 1943), Gil-Rodionov 1st Russian People's brigade of the SS (2500 personnel, August 1943). Summarily, about 7 thousand people of miscellaneous anti-Soviet formations joined the Soviet partisan force. About 1.9 thousand specialists and commanders were inserted in the Belarusian lands in 1943. However, the local people comprised the core of the personnel influx in the Soviet partisan force. In late May 1943, Uderzeniowe Bataliony Kadrowe, with permission of the headquarters of the Home Army, concentrated its forces (200 men) around Wyszkow. The Germans soon found out about it and surrounded the