I’m no politologist or military strategist, but I’m pretty sure a lot of wars (not all of them) are started so that a nation’s government can get better control over their own population. If the state can declare an emergency situation, they can use it to justify cracking down on political dissidents, invasive surveillance, restrincting freedom of speech, etc in the eyes of the public. It can also be used to ramp up nationalism, which works in the ruling class’ favour. Pretty sure this is at least part of the reason behind putin and nettanyahu stirring shit up right now.