War: The Death of us all

There is no such thing as an art of war. All it is is the bloody death of thousands, ever millions. The reason for most wars? A difference in ideas. I’m not saying that all everyone has to have the same ideas as everyone else, but you don’t have to go around killing their people because of it.
We may all be different, but we’re all the same in many ways too. We all love, we all have hearts. So why don’t we love instead of fight. If we all put down our guns and picked up tools instead, not only would fewer people die, but we could end world hunger, save the Earth, even cure cancer. So when will we end it all for the good of humanity? When will we end the fight?