Trade and the predatory state: Ricardian exchange with armed competition for resources—a diagrammatic exposition

Armed conflicts—especially wars—between/among nation-states, considered as monolithic wholes, surely reduce the mutual benefit they enjoy from trade. That common sense is virtually self-evident. Wars destroy trust that is essential to trade, wars and preparations for war absorb resources otherwise available for productive investment and exchange. Wars destroy people, their capital, and land. Anticipation or fear of war distorts free exchange, causing nations to protect domestic production. Accordingly, I was surprised and puzzled, when attending a seminar by Professors Garfinkel and Syropoulos (Trading with the enemy, Memo of March 1, 2017, Department of Economics, University of California-Irvine, Irvine, CA) to learn of a rigorous mathematical model that entailed mixed motives in international systems that might lead at once to armed conflict among states which nevertheless simultaneously benefit from mutual trade. So here I develop a primitive Ricardian model to explore how incentives to trade interact with those of predation. Its primary purpose is heuristic: to assemble the components of Ricardo, present them in a manner that specifically incorporates opportunities for appropriation through armed conflict, and shows how the component working parts fit together. Importantly, the paper builds the simplest possible model for the case at hand. Methodologically, the steps are geometric/diagrammatic with only ancillary attention to mathematics. The aim is to construct and explore the simplest possible classical, old-fashioned model that could permit analysis of those trade-predation linkages that seem to permit so unexpected a conclusion.