I think two factors that impede justice in the past have been propaganda and one person having too much power.  Two factors that aid justice are people knowing what's right, and communities doing the right thing no matter what their against. When a person gets too much power over anything, they start to go crazy and seem to think that everything should go their way and tend to end up hurting people. Look at almost every dictator or warlord in history. The people that stop these tyrants are the people of the world that stand up for themselves and others. The kids who stop bullies, the countries that help refugees and people in danger, the people putting their lives on the line for the safety of others. Thats why, like in our field trip we learned about how Hitler was stopped. People standing up for what was right, and like ISIS and Al-Quaeda being stopped by those same people. The go-getters in life.