It is not from the benevolence of the butcher, the brewer, or the baker, that we expect our dinner, but from their regard to their own self-interest. We address ourselves, not to their humanity but to their self-love, and never talk to them of our own neccessities but of their advantages.

Thus, even if appeals to decency or justice fall to make the case for peace, the appeal to self-interest persists – theoretically, there is always a negotiated outcome that’s better than warfare for both parties.