JF Ptak Science Books  Post 2757 (expanding an earlier post) 

The bottom line of the 63-day-long Second Warsaw Uprising (August/September 1944) is that the Soviet Union allowed the Polish Home Army to fail, watching from its position across the Vistula as the Nazis and Poles slugged it out, both exhausting themselves, the Nazis ultimately defeating the Poles, eliminating most of the Soviet concern for the Polish military and government, allowing the Soviet Union to take the country over more completely when the time came a few months earlier.  It was the Soviets’ choice to see two enemies annihilate themselves to have more control over Poland and immediately turn it into a vassal state when it rolled into Warsaw in January, with 85% of the city destroyed (“at the moment of its fall practically the whole city was [razed] to the ground”) and 600,000 of the city’s population  dead, along with 80% of the Home Army. 

• Full text (though not from my copy) here, at Instytut Józefa Piłsudskiego w Londynie :http://pilsudski.org.uk/archiwa/dokument.php?nonav=&salatka=1&nrar=709&nrzesp=108&sygn=88&handle=709.238/632