Obama’s war may be too little, too late to save the Libyan rebels, but it falls within his constitutional powers. The Constitution does not give Congress the dominant hand in war, the Declare War Clause notwithstanding. Our revolutionary forefathers in 1776 obviously rejected the royal prerogative, and they tried out all kinds of experiments to weaken the executive branch. But when the framers wrote the Constitution eleven years later they restored an independent, unified executive with its own powers in the presidency.
The most important of these powers is to wage war as commander-in-chief and chief executive. Ever since, presidents and Congresses have recognized that the executive can start military hostilities without a declaration of war. The United States has used force abroad more than 100 times. It has declared war only five times. In domestic affairs, Congress makes policy and the president’s job is to faithfully implement the law. But in national-security affairs, the Framers reversed that relationship, so the nation could benefit from the speed and energy of the executive.
A president can and should build political support for war by going to Congress, even if he doesn’t need its constitutional permission — as George W. Bush did in 2001 and 2002 for the invasions of Afghanistan and Iraq. And Congress has the power to cut off funds if it disagrees, a power it can exercise simply by doing nothing.