The current international security environment is characterized by unprecedented uncertainty. In the Asia-Pacific, our allies adjust to China's rise and hedge against instability coming from North Korea. In the greater Middle East, the Syrian civil war draws in powerful state and non-state actors, Iran's weapons program worries its neighbors, the Arab Spring continues its uncertain course, and we see a growing Sunni-Shia split throughout the region. In Europe, the need for a strong North Atlantic Treaty Organization alliance has become clear as nations along Russia's periphery reevaluate their strategic alignments in the wake of the situation in Crimea. In Africa, weak states with ethnic and religious tensions set conditions for terrorist groups to operate with near impunity. It is in this uncertain and unstable world that U.S. military forces will operate for the foreseeable future.