Did political warfare exist before the modern nation-state? During feudalism, tribalism, or the ancient Roman/Greek era(s), were there forms of warfare that existed that don't now, or vice versa?

Realism obviously has a major influence in today's political-military thinking. Even self-professed true believers, whether communist or Islamist or fascist, are met with cynicism about their motives and their actions re-framed in the realist prism, which is a framework for nation-state conflict. But even fascism at its ideological core believed in warfare (and violence generally) as more than just diplomacy by other means- it was a purifying force for the individual and the nation. The state was the tool for war, not war a tool for the state.

A related question: when machines drive supply convoys, refuel unmanned aircraft, and perform increasingly more complex combat tasks, what happens to warfare? And when there are vast social changes - such as the displacement of factory workers, truck drivers, servers, and warehousing people - what happens to the political system? In some countries, the military forms a portion of the state's social welfare program, keeping the restless employed and off the street. Is that our future?