Two factors shape all discussions on security cooperation. First, when the Department of Defense (DOD) revised its security cooperation doctrine, it did so assuming a relatively unrestricted environment. Second, the Arms Export Control Act and the Foreign Assistance Act, statutory authorities supporting U.S. security cooperation with foreign governments, were largely developed during the Cold War. The former’s broad construct does not fully account for statutory authorities and the constraints of fiscal resources while the latter does not account for current global realities. Taken in combination, these two conditions limit the ability of the United States to use security cooperation for achieving its objectives in fragile or failing states. The resulting disconnect creates varied policy interpretations and gaps that must be closed for effective security cooperation in the 21st century. The purpose of this article is to highlight the security cooperation potential that organizations could use to meet our nation’s capacity-building strategic objectives, identify shortfalls in doctrine and authorizations, and propose solutions.