Person who tries to create war and/or is passionate about war

I think you’re looking for the term Warmonger, a person who encourages or advocates aggression towards other countries or groups. You weren’t very specific though

These people are known as warmongers. The main motive in their love of war is usually personal gain so some people begin wars so that they could sell more weapons or to earn more money by being mercenaries. Either way, warmongers look for war and travel around the world participating in wars, or they live in their homes and inspire people around them to support wars.