 Western and contemporary Polish accounts claim that Joseph Stalin deliberately withheld support for the Polish Home Army as he wanted the Home Army — supporting the Polish government in exile, a competition to the pro‐Soviet Polish Committee of National Liberation — to be destroyed.On 20 August the 1st Polish Army of General Zygmunt Berling joined the Soviet 47th Army.Red Army forces north of Warsaw finally advanced across the Bug River on 3 September, reached the Narew River the following day, and secured bridgeheads across that river on 6 September.