Why U.S. Security Depends on Alliances—Now More Than Ever
By Kori Schake, Jim Mattis, Jim Ellis, and Joe Felter

The world is not getting safer, for the United States or for U.S. interests. Even before the coronavirus pandemic, the 2017 National Defense Strategy described an international environment of increased global disorder, long-term strategic competition, rapid dispersion of technologies, and eroding U.S. military advantages. Protecting the United States requires a strategy of defense in depth—that is, of identifying and dealing with global problems where they occur rather than waiting for threats to reach American shores.