Compass Thoughts

I was wondering if there is another dimension to the Political Compass mentioned in my last post. What is the relationship between violence and the other two axes presented?

Violence could be another axis (z or vertical to x and y) with pacifism/aggression as polarities. Alternately violence is an outgrowth of an authoritarian need to control others' actions. Certainly Stalin, Hitler and Saddam Hussein used violence to control their countries. It would be interesting to see where other dictators are placed on the compass. Another morbid thought is how serial killers are placed.