Defecting against everyone you meet is a losing strategy in an iterated multi-actor prisoner's dilemma. Establishing and maintaining mutual trust, to cooperate with those who are willing to cooperate with you, is in a nation's interests.
As the old joke goes "Don't anthropomorphize countries; they hate it when you do that." There is no guarantee of continuity in leadership or national policy because of periodic leadership turnover (elections, etc.) so exactly what would a country be extending trust to?
There's even less of a guarantee when a nation's unsupervised services have a century of experience replacing uncooperative foreign leadership with "more friendly" puppets. Unfortunately such regime change doesn't seem to ever benefit the people of either the interfered or interfering nations...
This seems like a fairly accurate model of North Korea's approach to international relations, but not most others. Would you say that they've found the optimum strategy?
