The past two decades have been tough for strategists. Large-scale efforts in Central Asia and the Middle East did not bring the successes policymakers demanded, despite considerable blood and treasure expended, and though free of U.S. combat casualties, the record in both Europe and the Indo-Pacific is not much better. U.S. attempts to reset relations with Russia did not prevent invasions of its neighbors or stop significant Russian intelligence operations in cyberspace. The U.S. military buildup in the Indo-Pacific and clear redlines did not deter the People’s Republic of China (PRC) from militarizing the South China Sea, undermining U.S. alliances in the region, or from using the power of trade to reinforce China’s national security positions. In Latin America and the Caribbean, both Russia and the PRC made inroads with their traditional partners, muting efforts to unify the region’s commitment to democracy, cooperation, and transparency. And in Africa, U.S. and European efforts to squelch terrorism, aid developing economies, and become the partner of choice ran up against alternative proposals from Moscow and Beijing, as they continue to strengthen their positions beyond their regions. The limits of the United States’ ability to preserve its hegemony and restrain competitors have compelled the national security community to refocus on Great Power competition to inform strategy development at the regional level.