The article "Resort to War" is a comprehensive guide to understanding different types of wars from 1816 to 2008. The researchers analyzed over a thousand wars using standardized methods to identify patterns and causes of war. They categorized wars into interstate, extra-state, intra-state, and non-state conflicts. The study reveals trends showing which types of wars are increasing or decreasing over time and how they are connected. The findings provide valuable insights for students and researchers studying international conflicts.