“Situations evolve and we must adapt swiftly; as a leader your decision-making will be tested.” That is true for leaders at all levels of our Service and certainly true for our complex, interconnected world. Former National Security Advisor and Secretary of State Henry Kissinger provides a backdrop for taking decisive action in today’s world by writing about century-long trends in foreign policy. Looking at the world order over time is a useful thought exercise as we confront today’s global challenges.