The KGB has cut off all possible channels for passing information on human rights violations from the Soviet Union to the West and has virtually destroyed the network for gathering such information within the U.S.S.R. Gorbachev has cut the flow of emigres from the Soviet Union to a trickle. Only 1.140 Jews were allowed to leave in 1935. compared to the peak of 51.320 in 1979. Even fewer Jews914emigrated last year. Those who have expressed their desire to leave the Soviet Union. but are not allowed to do so. now comprise a suffering underclass. Many of those who seek exit visas lose their jobs. their children are harassed in the schools and expelled from college. Those who dare protest are punished more severely. Mr.