The global power balance is rapidly evolving, leaving the United States at a turning point with respect to its level of engagement and the role of its military. Some argue for an “America First” paradigm, with a large military to ensure security, while others call for a more assertive posture overseas. Some advocate for a restoration of American multilateral leadership and a strengthened role for diplomacy. Still others envision a restrained U.S. role, involving a more limited military. How does the military function in today’s international order, and how might it be balanced with diplomatic and foreign assistance capabilities?