I am talking mainly about the post World War 2 era and the establishment of the Geneva Convention and Human Rights which were designed precisely for that purpose.
There are rules of engagement, convention, the United Nations, protocol has to be followed by civilized nations before engaging in military action.
The Geneva Convention and Human Rights are flawed as they were introduced on the basis of countries going to war. This hasn't happened for the longest of time, and has served no other purpose than restricting the 'civilized' nations in their potential actions.
Rules of engagement are outdated and haven't existed anymore since urban-/guerilla-warfare, as the rules of engagement were established on the basis of two armies (:nations) going to war. The fact of the matter is that these 'civilized' nations you speak off willingly restrict their methods assuming they can expect the same from their enemy, which is not the case. Conventions are only functional in terms of taking the political and moral highground (based on Western values) and being able to justify interventions within boundaries to the Western population.
