War: What is it good for?

Many have said this to justify their reasoning for war. I think the only reason why people say this is because they lost hope in diplomacy and negotiation. This is horrible because many problems can be solved through communication. Although I recognize that war has helped many countries find independency and justice, I find that there are also wars that only harmed rather than benefit the people. For example, Iraq. Though there was a major threat of terrorism that originated from that country, there was no reason in massacring every native. Another point I'd like to make is that war not only makes a huge impact on our opposition, it also harms us. Our people, mothers, daughters, fathers, brothers, all of them are in danger of losing their lives for something that may seem noble, but is not in reality. Which leads to a conclusion that war is, on majority, a case of appearance versus reality. So tell me, war, what is it good for?