In the months preceding the 1920 Kiev Operation, the communist Party of Poland intensified the disintegrating activities in the Polish Military. the action had already been undertaken a year before. Provoking the anti-war atmosphere in the ranks of soldiers could have sabotaged not only Polish offensive plans but also could have spoilt a defensive campaign in case the Soviet army invaded Poland. Incapacitation of an enemy before a decisive attack was the core of disintegrating actives led by Polish communists at the turn of 1919 and 1920. Pacific attitude manifested by a part of soldiers, as well as internal dissensions between them and officers usually against their social background were suitable factors to arrange hostile actions. Skilful use of those circumstances facilitated revolutionary indoctrination the process of disintegration of the Polish army fanned by communist agitation was gradually developing despite of battles won by the Polish during the Kiev offensive. the situation went even worse while the Polish troops were retreating. the tendency changed dramatically after the successful Battle of Warsaw (1920).