Every four years, the Pentagon experiences a dramatic leadership turnover, as civilian appointees resign to return to civilian life or move to more senior jobs for an administration’s second term. This places significant pressure on the new team in the Department of Defense (DoD) to form quickly to meet the persistent national security challenges. We must realize that the world broadly is getting more complex, and with it so is the national security environment that U.S. defense leaders must address—and de-risk. How this environment will evolve is unpredictable, but I contend we should expect a future in which the most aggressive of our global adversaries, namely, China, Russia, Iran, and North Korea will continue to push against U.S. influence and the global promotion of liberty, free commerce, and human rights to advance their interests and to fulfill their own national visions.