Our question now is this: what should the military’s duties really entail?

Ok, team! You have waded through the many transformations of the United States armed forces from their colonial legacies until the Global War on Terror. Many, many, many times you have seen the scope of military operations grow and change to fit an evolving nation and its needs as a rising global superpower. We have finally arrived at the modern era of American military history. Our question now is this: what should the military’s duties really entail? The rapid military success of Operation Iraqi Freedom was followed by the extensive involvement of the Army in peacekeeping, occupation duties, and nation building. To what degree are these appropriate roles for our Army?
Guidelines
Your initial response should be 100-200 words in length, reflecting on the prompt above.