It's a remarkably complex issue. I would however say that the case that comes to my mind though is not the USSR but Dutch Colonial Indonesia, and the jailing a

It's a remarkably complex issue. I would however say that the case that comes to my mind though is not the USSR but Dutch Colonial Indonesia, and the jailing and exile of Sukarno for printing nationalist, anti-colonial material. This looks on the outside very successful regarding suppressing Sukarno. After all the Dutch succeeded in keeping him contained until the Japanese arrived. However in a closer look you see a slow and steady development of a network of support that Sukarno built in Sumatra while in exile, which was used to support his efforts on his return to Java. So I am not sure it is so clear. Another interesting example might be Gorbachev in Russia. Here's someone who was quite clearly a communist and a Marxist, who, nonetheless, was not above critiquing the existing Soviet system in relation to the West and in so doing exposed cracks that caused the whole system to collapse. Gorbachev of course built on Khrushchev in this regard, but it shows that what is important is the alliance and solidarity, and to the extent that non-violence is conducive to that (and it usually is) it usually is helpful.