The framers of the Constitution had a clear idea of how war should work. Although the President is "commander in chief" of the military, the Constitution states that Congress has the power "to declare war, grant letters of marque and reprisal, and make rules concerning captures on land and water."
During the Cold War, that rule gave way to a new, unwritten principle: Try and stop me. Presidents jumped into foreign conflicts without any public debate, and found that Congress was unwilling to assert itself. Even when the Obama administration asked lawmakers to pass a formal authorization for a war against the Islamic State, a war everyone supported and no one wanted to stop, Congress chose to do nothing.
