Army exists to win the nation's wars. That is and always should be its principal mission. Army's transformation White Paper, Concepts of the Objective Force, states, The Army must remain optimized for major theater war,1 with the presumption that this theater of war is overseas. But the Army has other priorities as well. preamble to the Constitution tells us that among our founding principles, our government exists to insure domestic tranquility, provide for the common defense, promote the general welfare, and secure the blessings of liberty to ourselves and our posterity. This statement of existential purpose implies a domestic emphasis--that we must be prepared to fight significantly different kinds of wars from what we think of today. Even after 11 September 2001, the modern concept of war for most American soldiers is something that is fought elsewhere for national security reasons, does not directly affect domestic safety, and does not affect the lives of the average citizens (other tha n our national preoccupation with 24-hour news stations). Yet homeland security is now a major focus of the nation, the Administration, and Congress, and the Army will play a major role in it. This new security situation, dominated not just by the need to project exceptionally lethal force overseas, but also to assist in homeland security, will force change on the military. While once a significant mission of the Army, protecting US citizens from attacks at home has not been a major concern for generations, and the Army has not organized or actively planned for this mission in recent memory. Yet the events of 11 September 2001 have caused us to recognize that many of the asymmetric attacks we prepare to confront in distant combat zones also can be perpetrated against our citizens at home. Homeland security is once again a front-burner issue for the nation. From a formal policy perspective, the 2001 Quadrennial Defense Review (QDR) arguably made homeland defense the Department of Defense's primary mission, and the QDR report states that preparing for homeland security may require changes in force structure and organization. (2) For over a century and a half, from the formation of the nation until World War II, defending the nation-proper from foreign or domestic attack was arguably the primary mission of the Army. (3) Strategists, primarily outside the Pentagon, are once again focusing on the military's role in homeland security, with such issues as the control, composition, and missions of the National Guard receiving significant attention. (4) Juxtaposed to this, almost the entire focus within DOD before 9/l1 was on changing the structure, doctrine, equipment, and supporting institutional functions of the military--what the Army used to call DTLOMS and the joint community now calls DOTMLPF (Doctrine, Organization, Training, Materiel, Leadership, Personnel, and Facilities)--through a process called transformation, with the purpose of being better able to fight future wars in faraway places. (5) Since 9/11 this has not changed substantially. For the Army, the ability to project transformed power to distant theaters of war is the major focus. Additionally, the Objective Force concepts for fighting future wars envision nonlinear battlefields, significantly faster operational tempo (optempo) and speed on the battlefield, nearly omniscient commanders and forces with a god's eye view of the battlefield based on almost perfect intelligence, and more sophisticated technology, including the expanded use of robotics. These two strategic focuses create institutional forces--transformation and homeland security--which will drive change in the Army. To date, indications are that they are being considered separately, without regard for their interactions or the realization that, together, they define the military capabilities needed in the new security environment. In this article, I briefly examine each and discuss how they affect expectations and capabilities, using the DOTMLPF model as a template. …