Congress declares war, raises and supports armies, provides and maintains a navy, regulates the armed forces, defines offenses against international law, and controls appropriations. Congress can also authorize force without a formal declaration of war, define a mission's targets or geography, require reports, limit funds, or repeal an earlier authorization. The president commands forces; Congress supplies major legal and fiscal foundations for their creation and use.

The distinction between command and lawmaking is essential. A president may direct the movement and tactics of forces that Congress has lawfully created and funded. The commander-in-chief title does not itself authorize spending Congress withheld, revision of the military code, seizure of domestic property, or displacement of every statute connected to national security. In Youngstown, the Supreme Court rejected President Truman's seizure of steel mills during the Korean War. Military responsibility did not give the president a general domestic lawmaking power, particularly after Congress had chosen different policies.

Presidents have nevertheless used force without declarations of war and have claimed a disputed sphere of unilateral action, especially to repel sudden attacks or conduct limited operations. The constitutional boundary is shaped by text, historical practice, statutes, appropriations, and the circumstances of the operation. Courts sometimes avoid the broadest interbranch disputes, which makes congressional authorization and funding especially important.

The War Powers Resolution adds statutory consultation, reporting, and timing rules, but it is not a grant of sixty days of free-standing presidential war power. A timely report gives Congress information and may start a termination clock; it does not itself authorize hostilities. Chapter 12 examines those procedures in detail.

When military facts appear, identify the exact question. Operational command points toward the president. Authorization, military regulation, and appropriations point toward Congress. A statute that expressly limits an action changes the Youngstown analysis. Avoid answers claiming that either branch owns every decision simply because the subject is war.

Video lesson: Presidential Power: Crash Course Government and Politics #11