The Soviet Red Army captured the almost completely destroyed Polish city of Warsaw
Despite standing for about 40 days less than 10 km from Warsaw's city center, and then moving even closer, to the right bank of the Vistula river a few hundred meters away from the main battle of the Warsaw uprising during its last two weeks, the Red Army did not extend effective aid to the desperate city.
The inactivity of the Red Army directly in front of Warsaw elicited this reaction of amazement from Germans, recorded in the operations journal of German 9th Army on 16 August 1944: Contrary to our expectations, the enemy has halted all of their offensive actions alongside the entire front of the 9th Army.
The Red Army reached the outskirts of Warsaw in the final days of July, 1944. The Soviet units belonged to the 1st Belorussian Front, participating in the Lublin-Brest Operation, between the Lvov-Sandomierz Operation on its left and Operation Bagrationon its right. These two operations were colossal defeats for the German army and completely destroyed a large number of German formations. As a consequence, the Germans at this time were desperately trying to put together a new force to hold the line of the Vistula river, the last major river barrier between the Red Army and Germany proper, rushing in units in various stages of readiness from all over Europe.
Research into the lack of support of the Warsaw Uprising is (according to historians such asNorman Davies) currently very difficult due to lack of access to archives. For records relating to the period, currently both the United Kingdom archives and Russian archives (where the majority of Soviet archives are kept) remain mostly closed to the public. Further complicating the matter is the United Kingdom's claim that they accidentally destroyed the archives of thePolish Government in Exile.
Sources: wikipedia.org, news.lv