Hmm..last i checked Socialism failed everywhere it's been planted.
Lenin kill who opposed him?
Stalin mass slaughter and famine enemies oh and purged disagreements.
Mao caused the great leap forward and cultural revolution which killed many..not too mention many resisters were killed during martial law in China.
Laos and Vietnam most of it is wilderness were the members do not contribute to society and just eat their makings..more-so-ever anarchist.
Cuba leader Fidel Castro is a decent socialist leader, i must say, but he still purged enemies, but he was near one semi-fair leader.
Don't get me started on North Korea...were all that ever happened there was death, people try to run the cops fucking kill them, oh and their death/work camps.
Please don't intertwin Trotskyism into this system of "a way to fix things" considering that im sectarian, i beileve the system is the system no matter what way you look at it.
Let's also look at this from a common sense point of view about communism, if one specific leader did unit the world under socialism, your anticipated he would give up the entire world? It's his now, and his army would still be there...who would stop him? No..one..
Communism is good in philosophy just like Fascism (heritage above hate) and anarchist (live and let live) but as we can see from practice, they don't work!