The exile government was dependent on the support of the British and American governments , which did not grasp Communist intentions and pressured the exile government to cooperate with the KRN . By the time of the Yalta Conference in February 1945 , Soviet forces had overrun nearly all of Poland , giving them and the KRN effective control . The US and Britain tacitly accepted this at Yalta , in return for Stalin 's promise of free elections in Poland
Yalta Conference
Yalta Conference
Provisional Government of National Unity