only in the last 150 years or so, have states agreed on international laws to limit warfare. this has been mainly for humanitarian reasons. the geneva conventions and the hague conventions are two examples of agreements that establish laws governing wars. collectively, these are usually called international humanitarian law (ihl). because these are established laws, they restrict those engaged in armed conflicts to follow the ihl. also, a country must not only respect the law but they also need to make sure other countries respect it as well. they cannot turn a blind eye (meaning pretend they do not see a thing) to countries who are not following ihc. the first of these was the geneva convention in 1864. it became international law with the signatures of 100 countries.