Hi, world history is full of events, some god event and some bad. Some wars and some peaces. By studying the history we can learn about the harm of the war and the beauty of the peace and how we can develop faster in peace. Specially now that the earth is a global village. Totally the reason of wars is that two side have some conflict, one side want something and then other want dot, when they are agree they might fight, but no war can be the best solution. We just lose by war even if we win in war. Here we have a video about causes of world war 1.