Socialism contains within it pressures against war and dictatorship, while Capitalism contains within it pressures towards war and dictatorship. Socialism alone wouldn’t outright eliminate dictators and war, but would go a very long way towards eliminating them over time.
The only one of these I can see socialism eliminating is unemployment. You can easily have dictators and wars with socialism.
Socialism contains within it pressures against war and dictatorship, while Capitalism contains within it pressures towards war and dictatorship. Socialism alone wouldn’t outright eliminate dictators and war, but would go a very long way towards eliminating them over time.