Ka kammala wannan jumlar: Ƙasar Rasha ta Dā ta mamaye gabashin Poland a ranar 17 ga Satumba, 1939, makonni biyu da rabi bayan mamayar da Nazi Jamus ta yi wa Poland a ranar 1 ga Satumba. An yanke shawarar kai hari guda biyu a cikin asirin Molotov-Ribbentrop Pact wanda USSR ta sanya hannu tare da Jamus a watan Agusta 1939. Kamar yadda yawancin sojojin Poland suka tattara a yammacin ƙasar don yaƙi da Jamusawa, Soviets sun haɗu da ƙarancin juriya kuma dakarunsu sun hanzarta matsawa yamma har sai sun isa Brześć a ranar 22 ga Satumba, inda suka haɗu da sojojin Jamus masu mamayewa kuma suka riƙe
bikin baje kolin nasara tare.