The double genocide theory is the idea that two genocides of equal severity occurred in Eastern Europe, that of the Holocaust against Jews perpetrated by the Nazis and a second genocide that the Soviet Union committed against the local population. The theory first became popular in Lithuania in the early 1990s. A more aggressive version of the theory accuses Jews of complicity in Soviet repression and characterize local participation in the Holocaust as retaliation, especially in Lithuania, eastern Poland, and northern Romania.