how international relations really works. It is quite different from what most people imagine. Countries behave in a more self-interested and less considerate way than what most of us would consider appropriate for individuals. When countries negotiate with one another, they typically operate as if they are opponents in a chess match or merchants in a bazaar in which maximizing one’s own benefit is the sole objective. Smart leaders know their own countries’ vulnerabilities, take advantage of others’ vulnerabilities, and expect the other countries’ leaders to do the same.