i'm not sure, stalin would a further incursion right after ww2, it would be very silly because ussr lost a lot of power after the war, well, who knows... ussr got the nuclear bomb in 3 years after usa got it (usa just bought it, ussr stolen it).
the thing i understand is that killing a some one is not a solution of a problem. even stalin said once "there is no any man who can't be replaced by another one" (my translation).
also, there is no simple solution to get out of chaos that we got in the world.
the question goes more bigger, it's not about just hitler now. and hitler didn't kill anyone personally, so, it's actually people's fault, hitler is just a symbol of the disease. the same about stalin.
now we need to point out what we actually want to know -
"will there another hitler?", i'll say "yes, but he'll never get the power hitler had"
"will be there new people's mistakes?", "yes".