On 25 July, the Union of Polish Patriots, in a broadcast from Moscow, stated: “The Polish Army of Polish Patriots ... calls on the thousands of brothers thirsting to fight, to smash the foe before he can recover from his defeat ... Every Polish homestead must become a stronghold in the struggle against the invaders ... Not a moment is to be lost.”
On 29 July, the first Soviet armoured units reached the outskirts of Warsaw, where they were counter-attacked by two German Panzer Corps: the 39th and 4th SS.
On 29 July 1944 Radio Station Kosciuszko located in Moscow emitted a few times its “Appeal to Warsaw” and called to “Fight The Germans!”: “No doubt Warsaw already hears the guns of the battle which is soon to bring her liberation. ...
The Polish Army now entering Polish territory, trained in the Soviet Union, is now joined to the People’s Army to form the Corps of the Polish Armed Forces, the armed arm of our nation in its struggle for independence. Its ranks will be joined tomorrow by the sons of Warsaw. They will all together, with the Allied Army pursue the enemy westwards, wipe out the Hitlerite vermin from Polish land and strike a mortal blow at the beast of Prussian Imperialism.”
The Uprising began on August 1st. The Soviets gave all indications they would assist if the Uprising took place.
Thank you!
I understand it might look controversial from the moral perspective but there were no negotiated support promised. Also the Soviets were fully aware that UK is planning to fly the anti-Soviet government to Warsaw following the uprising. To postpone attack was a sort of real-politic. Legally based on the norms of foreign policy they did nothing wrong.