Hold on. Communism with dictators historically came about by what we call war communism. Is this what you are referring to.
In theory, the basic philosophical teaching were this: Someone wants to implement some form of communism. Capitalist societies feel that will 'infect' their region and thus must shut it down. Again, the example of the arms race. What happens is, you will not be able to get your country to communism if a threat is coming.
Only choice: devote all resources to the military: kills the economy, but saves the country. In order to do war communism, you need a leader who must make quick decisions because he doesn't have time to educate everyone else on what is going. This is the original definition of a dictator.
-->So, I say if there is no threat of war or oppression like a war, then a dictator will not rise up. We have yet to see an example of this. The reason dictators don't step down after a war: power feels great.
---> I am still going to argue right now (not my belief personally) that soviet socialism would still work as long as there is no dictator.