The Soviet Union had created an alternative, puppet government in 1944 (the Polish Committee of National Liberation) and ensured it formed the basis of the post-war government in Poland. During the Soviet-backed communist takeover of Poland at the end of the war, many Underground State members were prosecuted as alleged traitors and died in captivity. Abandoned by the Western Allies, finding it impossible to negotiate with the Soviets, and wishing to avoid a civil war, the key institutions of the Underground State dissolved themselves in the first half of 1945.