 This merged into the 1919–1921 Polish–Soviet War, in which the Red Army reached central Poland in 1920, but then suffered a defeat there, which put an end to the war.During the Polish Campaign the Red Army numbered some 6.5 million men, many of whom the Army had difficulty supporting, around 581,000 in the two operational fronts, western and southwestern.Around 2.5 million men and women were immobilized in the interior as part of reserve armies.