The democratic republic of Korea is the way it is because of US foreign policy of overthrowing governments they don't like. North Korea also has a success story to tell, their citizens are not subjected to war. Their are many countries in the world right now that are not able to protect their citizens like that.
The idea that we can't have communism until everybody agrees is stupid, do you really think all those capitalist billionaires would ever give up their privilege to plunder the world and exploit its people, willingly ? Capitalism is torturing billions of workers with exploitation, every year 10s of millions of people are murdered with systemic violence, hundreds of thousands to millions more are destroyed with physical violence. Once all those people had enough of the despair, the suffering, the political disenfranchisement, the pointless toiling for the rich, the pointless dying… and they establish a system that works for the masses, it will be justice. And you don't get to judge the means by which this is achieved, unless you can do better and lead by example. Because the system as it is now sure as hell is not based on voluntarism.
You would be telling the people being slaughtered by fascism in WW2, that if they defend them self it's not justice unless all the Nazis agree with it.
Most communists and socialists have as personal characteristic, a strong sense of moral principle, and you are a liberal trying to use that against us.