Large-scale warfare does not arise from capitalism. It was started by communist regimes as well and, moreover, existed long before capitalism and communism came up. Large-scale warfare also does not arise from modern nation-state formations. Premodern rulers waged large-scale wars as well. Warfare originates from the genetic makeup of humans, even of our predecessors the chimps, and got amplified by societal developments that came with agriculture over the last 12,000 years.