The era of untrammeled U.S. military superiority is over. If the United States delays implementing a new approach, it risks losing a war to China or Russia—or backing down in a crisis because it fears it would—with devastating consequences for America’s interests.
The U.S. Defense Department’s 2018 National Defense Strategy initiated a needed course correction to address this challenge. As then-Defense Secretary James Mattis put it in January that year, great-power competition—not terrorism—is now the Pentagon’s priority. But while the strategy’s summary provides a clear vision, it leaves much to be fleshed out. What should this shift toward great-power competition entail for the U.S. military?
To answer, we must first understand the current geopolitical landscape. As ever, the foremost concern of the United States is to maintain adequate levels of military power; without it, there would be nothing to protect Washington from the worst forms of coercion and every incentive for ambitious opponents to exploit the ensuing leverage. Largely for that reason, the United States has an enduring interest in open access to the world’s key regions—primarily Asia and Europe—to ensure their latent power is not turned against it. The United States does so by maintaining favorable balances of power in these regions through a network of alliances. These partnerships are not ends in themselves but rather the way the United States makes sure that no state dominates these critical areas.
Russia and especially China are the only countries that could plausibly take over and hold the territory of Washington’s allies and partners in the face of U.S. resistance. If they did so—or even if they merely convinced their neighbors that they could and then used that fear to suborn them—they could unravel U.S. alliances and shift in their favor the balances of power in Europe and Asia.