The correct answer to this question is true – There was collapse of Imperialism and self-determination in former colonies after World War II. After the end of the Second World War in 1945, many nations mostly in Asia and Africa rejected being under the colonial system. They campaigned for their independence rather than remain under the European colonial system. Between 1945 and 1960, many nations had gained their independence and were complete out of the colonial system; their decisions and governance were self-determined.
As at 1946, there were about 35 members of the United Nations as the newly independent members were now part of the UN. By 1970, the number had drastically moved up to 127. These nations were regarded as “third world”. After the collapse of imperialism, many of these nations were working to develop their economies and resolving problem that arose as a result of the past colonial rule.
You overlook the Soviet absortion of eastern Europe and the partitioning of Germany itself. You are a progressive aren't you? You even mentioned fascist Spain in the questions; it remained fascist until the death of Franco.
I entirely sisagree on that statement because the aftermath of the second world war was to establish two giants the United States of America as well as the Soviet Union which took full power over Europe, the Soviets especially by creating the notorious Iron Curtain.