Different people gain and lose different things from wars, it is extremely fluid. Companies in the defense industry are likely to see a short to medium term spike which benefits them. Politicians who tell their armies to fight at the highest levels are often far beyond wanting any monetary riches from it, certain wars become ideological and are based on power projection, even if they do come across as incompetent they can kill a lot of people in the process. There are plenty of industries that also suffer from war, like we see record oil prices right now (bad for the general consumer) and there may be disruption to certain commodities like wheat or precious metals. In such cases mining companies who can supply from a further limited source may do well.