The 2024 Annual Estimate of the Strategic Security Environment sets the foundation for cutting-edge research to understand the ever-evolving security environment domestically and internationally. Competition with the People’s Republic of China continues to dominate the strategic narrative, with global implications for US national interests. The Russia-Ukraine War and the deteriorating situation in the Middle East, however, present immediate and political challenges that will undoubtedly influence US military efforts abroad. At the same time, the United States faces domestic challenges in navigating civil-military relations, and the Army is working diligently to overcome institutional hurdles. The United States published its first National Defense Industry Strategy in January 2024, focusing on resilient supply chains, workforce readiness, flexible acquisition, and economic deterrence. Additionally, the Army released the 2024 white paper “Army Force Structure Transformation,” which lays the groundwork for creating new capabilities, initiates new recruitment modernization efforts, and justifies challenging personnel reductions across the force. Finally, the prevalence of competition in new and maturing arenas (such as space and the polar regions) may impact a delicate balance among the great powers. This balance, and the potential relative advantage the United States maintains over its adversaries, is further challenged by emerging technologies, many of which have yet to realize their impact on defense operations.