National security leaders rarely get to choose what to care about and how much to care about it. They are more often subjects of circumstances beyond their control. The September 11 attacks reversed the George W. Bush administration's plan to reduce the United States' global commitments and responsibilities. Revolutions across the Arab world pushed President Barack Obama back into the Middle East just as he was trying to pull the United States out. And Russia's invasion of Ukraine upended the Biden administration's goal of establishing "stable and predictable" relations with Moscow so that it could focus on strategic competition with China. Policymakers could foresee many of the underlying forces and trends driving these agenda-shaping events. Yet for the most part, they failed to plan for the most challenging manifestations of where these forces would lead. They had to scramble to reconceptualize and recalibrate their strategies to respond to unfolding events. The rapid advance of artificial intelligence—and the possible emergence of artificial general intelligence—promises to present policymakers with even greater disruption. Indicators of a coming powerful change are everywhere. Beijing and Washington have made global AI leadership a strategic imperative, and leading U.S. and Chinese companies are racing to achieve AGI. News coverage features near-daily announcements of technical breakthroughs, discussions of AI-driven job loss, and fears of catastrophic global risks such as the AI-enabled engineering of a deadly pandemic. There is no way of knowing with certainty the exact trajectory along which AI will develop or precisely how it will transform national security. Policymakers should therefore assess and debate the merits of competing AI strategies with humility and caution. Whether one is bullish or bearish about AI's prospects, though, national security leaders need to be ready to adapt their strategic plans to respond to events that could impose themselves on decision-makers this decade, if not during this presidential term. Washington must prepare for potential policy tradeoffs and geopolitical shifts, and identify practical steps it can take today to mitigate risks and turbocharge U.S. competitiveness. Some ideas and initiatives that today may seem infeasible or unnecessary will seem urgent and self-evident with the benefit of hindsight.

As ample wargaming and analysis have shown, any war with China would be economically and strategically costly, as well as fraught with the risk of escalation to nuclear war. In addition, any U.S.-China military conflict could very likely last longer than envisioned by traditional force planning scenarios, which often are designed around relatively limited objectives and call for U.S. forces and capabilities that could bring a war to a quick, decisive conclusion. This report describes a set of scenarios of such protracted conflicts and provides what could be a foundation for more-detailed planning or analysis. To allow free creative scope for the scenario development process, the authors did not place a priori constraints on the meaning of “protracted,” and therefore, the resulting scenarios feature a variety of circumstances in which the United States and China could be required to sustain military operations on much longer time frames.