A case of high school civics gone awry in the popular imagination.
Q: Korea and Vietnam were unconstitutional because there was never a declaration of war, right?
A: Nothing in the Constitution requires that hostilities be accompanied by a document entitled “Declaration of War.” Even in the most expansive reading of what this process requires, it is Congressional assent. One could argue that by funding the conflicts, Congress gives consent. And since this is something a court will never decide, that’s pretty much all there is to it.
Q: But the country can’t engage in hostilities without a declaration of war, right?
A: Wrong. A “declaration of war” is a term of art in international law. By declaring it, you’re putting certain people on notice of things you’re going to do, like, say, sink their ships, detain their nationals, and so on. It is not the case that the President can’t use military force without one. Since the beginning of the Republic that has been the case. Adams, Jefferson, and Madison all used the military without a declaration of war. Use of the military goes back almost as far without any kind of congressional authorization, especially if you count uses of the military against Indians, which, I have no idea why you wouldn’t.
Q: Can’t Congress impeach the president for this? or for not following the War Powers Act?
A: Sure. Congress’s ability to impeach the president only requires that a vote be held. It’s not invalid if they don’t specify a statutory high crime or misdemeanor, because no court will test it, and they might do so on the pretext of the War Powers Resolution/Act, but there’s not much doubt that, strictly speaking, that resolution is unconstitutional, but it provides a guideline for where Congress thinks they should come into play. Its constitutionality doesn’t matter because nothing says that an impeachment can only be for something unconstitutional.
Q: If the President can use the military without Congress, then why is that part of the Constitution, that only Congress can declare war?
A: In the British Constitution, the King declares war and often did so for purposes of conquest. At the time, declaring war could cause one because there wasn’t often a standing army. So, in our day, the fact that Congress funds a full time military more or less means that they are giving away the game. In other words, if there’s no army and the president can declare war, he puts Congress in a position of probably having to raise an army to defend the country, potentially on the President’s whim.
But once there is an army, the President has the Constitutional power to use it. We just live in a different time.
If there was any power that might be limited, you’d think it would be the deployment of the country’s nuclear forces. You’d think that might require the assent of the Speaker of the House, or something. But it doesn’t, and it probably can’t unless you want to risk not being able to respond, which actually invites an attack.
But once you realize that the President can nuke, it seems silly to me to quibble over whether the words “Declaration of War” need to be on a piece of paper.