Since the 1950s, the United States has fielded a Triad of air-, sea-, and land-based nuclear delivery systems. After decades of service, major components are nearing the end of their service lives. This Perspective describes the role of the Triad in U.S. nuclear weapons policy and presents an overview of the current debate over the Ground-Based Strategic Deterrent program to replace the aging Minuteman III intercontinental ballistic missile.