From east Timor to el Salvador, from Iraq to Somalia, passing by the Yugoslavia, the civil war is the type of conflict the most common since 1945. Often longer and more bloody than wars between States, civil conflict can also have deleterious effects on the neighbouring countries, as we have seen with the syrian crisis. Therefore, it is vital to understand the fact that a civil war begins. Sophie Panel and Raul Magni-Berton, two researchers, have written a book on this question, The Choice of weapons (ed Presses de Sciences Po), which shows both the importance…