The change tasked the Department of War (DoW) with actions traditionally in the homeland security domain. A future scenario where DoW is simultaneously in combat operations and supporting, or even leading homeland emergency management operations, demands enhanced integration of the homeland security and homeland defense enterprises. The core concept of military homeland defense doctrine is a defense posture integrated across three geographic layers: forward regions, approaches, and the homeland. The homeland defense approaches layer extends from the homeland layer outward to the forward regions, in which USNORTHCOM has the preponderance of homeland defense responsibilities. The final homeland layer, comprising all U.S. territory, includes the joint force combined with all U.S. Government agencies, integrating homeland security and homeland defense plans, operations, exercises, and capabilities.