There is an ongoing debate as to whether war contributes to human progress or not. The pro side argues that war creates competition among nations, tribes, cultures, etc. The cynical evolutionary push drives us to invent ever more deadlier weapons to outdo our adversaries and that in turn leads to inventions with civilian uses. The con side states that there can be no progress for the masses in war only for the elite who benefit economically from any new inventions derived therefrom. Still, advances in warfare technology have changed the course of history, not necessarily for the benefit of mankind. Here are the weapons that have changed history.