Complex sentence: This was due to a strong aversion from many in the group to embrace Stalin and Communism; they now viewed the Soviets as fellow fighters against Hitler and fascism; the Soviets were allies of immediate necessity, not true allies.
Split into simpler sentences: This was due to a strong aversion from many in the group to embrace Stalin and Communism. They now viewed the Soviets as fellow fighters against Hitler and fascism: the Soviets were allies of immediate necessity, not true allies.