Once remarked that "Any anti-communist is a dog!" Tried to use his influence to promote the absurd argument that North Korea didn't start the Korean War. Argued that intellectuals should ignore the evidence of the rise of the Soviet
forced-labor camps, because talking about them might play into the hands of the French
right. As millions starved to death in the camps, Sartre wrote: "As we were neither members of the party nor avowed sympathisers it was not our duty to write about Soviet labour camps; we were free to remain aloof from the quarrel over the nature of this system, provided no events of sociological significance had occurred." Unfortunately Sartre was very influential at the time he made these arguments, and many western intellectuals who agreed with this thinking played dupes for
Stalin.
Speaking for herself and Sartre, Simone de Beauvoir once wrote (in The Prime of Life) that she and Sartre were "temperamentally opposed to the idea of reform," because peaceful change was less sanguine to their temperaments than violent revolution.
I disagree with your suggestion that the Soviet Union was only revealed as evil when Khruschev gave his "secret speech." First of all, the speech was extremely slanted. It only dealt with Stalin's abuses which were directed at party members. He had nothing to say, for instance, for the 7 million Ukranians wiped out by a deliberately planned regional famine. Kruschev's motives were more political: he wanted to protect his power by discrediting those who aligned themselves with Stalin's positions on various arguments (such as the organization of the Comintern). Secondly, there were numerous accounts of the horrors that had gone on in the Soviet Union. People like Sartre simply chose to ignore them, unless perhaps they came from someone who happened to be a Soviet communist himself. It is a fact that Sartre only admitted that torture existed in the USSR when Kruschev said it had. But before this event, he helped to discredit and humiliate the first-hand witnesses of such abuses. Interestingly, Sartre didn't display such fervent skepticism regarding accusations of terror involving his own government.