The problem is that the Soviet government lied about the connections between political dissidents and foreign governments. In Vishinsky's summary speech to the 1936 Moscow Trials, he said, "Terror was the basis of all their activities, it was the basis of the Trotskyite-Zinovievite union. This was quite unanimously testified to by people who were not directly connected with each other in their underground work. This was not only admitted here by Zinoviev and Kamenev, Smirnov and Ter-Vaganyan, Reingold and Pickel; it was stated also by Berman-Yurin, Fritz David and Valentine Olberg, that peculiar citizen of the Republic of Honduras, paid agent of Trotsky and simultaneously of the German secret police - the Gestapo."
Now the notion of any of these people being on the payroll of the Gestapo is just a sick, insane lie. In truth Trotsky was one of the leading opponents of Nazism in the world. Three years after Vishinsky stated these lies, the Soviet Union and Nazi Germany signed a non-aggression pact, which is not an unprincipled thing to do. What was unprincipled was Stalin's instructions to Communist Parties to mute anti-fascist agitation. That was a crime.
Louis Proyect
(http://www.panix.com/~lnp3/marxism.html)