U.S. Army Training and Doctrine Command TRADOC Pamphlet 525-8-5 The U.S. Army Functional Concept for Engagement, expands on the ideas presented in TP 525-3-0, The U.S. Army Capstone Concept (ACC), and TP 525-3-1, The U.S. Army Operating Concept (AOC), and introduces a new warfighting function. The complexity and uncertainty in the global environment means the Army must become more agile, flexible, and well-prepared to tackle a broad range of operations through the development of innovative, low-cost, and small-footprint approaches to achieve U.S. security objectives. The Army also must possess a broad range of capabilities to shape future operational environments, maintain its lethality on the battlefield, and be able to leverage unified action partners to reduce demands, prevent, and end conflict. The engagement warfighting function will institutionalize into Army doctrine, training, education, and leader development, the capabilities and skills necessary to work with host nations, regional partners, and indigenous populations in a culturally attuned manner that allows bridging language barriers, opening lines of communication and connections with key political and military leaders in a way that is both immediate and lasting. It enhances interdependence between special operations forces, conventional forces, and unified action partners while incorporating the tenets of the emerging idea of the human domain. As a result, this warfighting function will contribute to mission accomplishment by providing better, more synchronized lethal and nonlethal capabilities to assess, shape, deter, and influence the decisions and behavior of a nation's security forces, government, and people. TP 525-8-5 effectively complements the six other warfighting functions and is fully nested in the broad vision outlined in both the ACC and AOC. This concept will lead force development and modernization efforts by establishing a common framework to capitalize on the integrative opportunities all of the warfighting functions provide to future land operations.