The continental world of warring spheres of influence is 'negative sum' because in territorial warfare, goods get damaged in the fighting—whatever the loser's loss is becomes damaged goods, making the winner's win a partial loss; the maritime world by contrast enables 'positive sum' transactions where trade makes both parties better off, trade requires trust (you won't ruin your customer or they won't return), and international law facilitates trade by minimizing transaction costs; maritime powers focus on trade and markets rather than territorial confiscation, avoiding the 'headache' of running other people's businesses