That's not really true. A full-scale war is necessarily conducted by both the state and the nation. Even autocrats need the blessing of the general population t

That's not really true. A full-scale war is necessarily conducted by both the state and the nation. Even autocrats need the blessing of the general population to successfully prosecute such a war, otherwise he runs the risk of the people rebelling and shutting down vital infrastructure just when they need it most. You can't have your army in two places at once, quelling the populace and fighting the enemy. Full-scale war intensely taxes everyone's resources. Also soldiers won't fight with the zeal they need to be effective against soldiers defending their homeland unless they really believe in what they're doing. Hence the general move before and after the two world wars towards more limited war. With a limited war, you have to rely on professional, volunteer soldiers to conduct operations. Many nations conscript, but largely to keep readiness up. It's difficult to conduct the sorts of operations you see in the small-scale military operations of today with a conscript army. These are people with jobs and lives, they just won't be able to give their all. Big wars only happen after long-term feedback loops of media coverage rousing national anger against other nations make it politically feasible to actually declare war. These wars truly are everybody's affair.