Normally, one would expect the voice calling the loudest for an American declaration of war to come from the hawk caucus, not the non-interventionists. After all, the US has not issued a formal declaration of war since World War II, although we have yet to have a decade without some kind of armed clash ever since. This time, though, the call to arms against ISIS comes from Senator Rand Paul, whose history of criticism about American military adventurism abroad makes this a rather large surprise:

Senator Rand Paul is calling for a declaration of war against the Islamic State, a move that promises to shake up the debate over the military campaign in Iraq and Syria as President Obama prepares to ask Congress to grant him formal authority to use force.

Mr. Paul, a likely presidential candidate who has emerged as one of the Republican Party’s most cautious voices on military intervention, offered a very circumscribed definition of war in his proposal, which he outlined in an interview on Saturday. He would, for instance, limit the duration of military action to one year and significantly restrict the use of ground forces.

Unlike other resolutions circulating on Capitol Hill that would give the president various degrees of authority to use force against Islamic militants, Mr. Paul would take the extra step of declaring war — something Congress has not done since World War II.

The president has said he will ask Congress for the explicit authority to fight the Islamic State, though administration officials have insisted that he has the legal power to continue the current campaign. That position has rankled many in Congress who are concerned that the White House has been waging war without the proper oversight or accountability.

The problem with this approach, though, is that a formal declaration of war actually unlocks more executive authority than it restricts. One reason that Congress has used AUMFs over the last several decades was certainly a lack of political/intestinal fortitude, but another is that it limits the President in his warmaking authority. A properly-crafted AUMF could keep a Commander in Chief within the bounds Paul wants, but a declaration of war would make it difficult to restrict decisions like ground-force deployment and length of commitment.

For that matter, why would a declaration of war come with an expiration date? Republicans rightly climbed all over Barack Obama for announcing withdrawal dates in Iraq and Afghanistan well before the conflicts in both countries ended, and this concept is no different at all. When Congress declares war, the country fights until victory, not until a Google alert tells us to withdraw. A formal declaration gives the President not just legal authority to make command decisions he feels necessary to win the war, but also moral and political authority that would put Congress at a massive disadvantage if it tries to rescind the declaration in the middle of fighting. That’s also true of an AUMF, but to a much lesser degree.

The Daily Beast tries to make sense of this apparent reversal by Paul, especially after publishing an essay in which Paul demanded that Obama either ask for a formal declaration of war or disengage against ISIS:

Perhaps most surprisingly, Paul’s resolution will allow for limited use of boots on the ground “as necessary for the protection or rescue of members of the United States Armed Forces or United States citizens from imminent danger [posed by ISIS]… for limited operations against high value targets,” and “as necessary for advisory and intelligence gathering operations.”

In an interview with The Daily Beast in September, Paul said he was against the idea of U.S. forces on Middle East soil. “I don’t think there needs to be any American soldiers over there on the ground,” he said. “I don’t mind helping them through technical support, through sophisticated intelligence, drones, Air Force, etc.”

He added: “The people on the ground fighting these battles, going hand-to-hand with ISIS, need to be their fellow Arabs and those who, I think and hopefully do, represent civilized Islam.”

Doug Stafford, a senior aide to Paul, said the senator has not flip-flopped: “He doesn’t believe we should send a bunch of troops in to start a ground war. But he has always said we have an obligation to defend people in the region. The declaration is tailored to allow for this.”

Isn’t this the kind of double-speak that Paul and his father used to protest against? Stafford sounds as though he’s hinging the change on the definition of “bunch,” and possibly “start.” The ground war is already in motion, and has been all year long in Iraq and Syria. The parsing of mission terms in which Stafford and Paul fils now engage would have gotten ripped by Paul as a “slippery slope” into a repeat of Vietnam in any other circumstances.

Margaret Hartmann at New York Magazine thinks this is contrarian performance art:

For months, Rand Paul has been trying to shake claims that he is an isolationist like his father. His recent op-ed “I Am Not an Isolationist” didn’t do the trick, so this weekend the Kentucky senator told the New York Times that he wants to formally declare war against ISIS. The president will soon ask Congress for authorization to fight the terrorist group, though that effort is already well underway. “War cannot be initiated without Congress,” Paul said, arguing that conservatives should be more upset about that unilateral action by Obama. “Conservatives are mad at him about immigration. And they’re mad about him using executive authority on Obamacare,” he said. “But this is another example where he doesn’t have much respect for Congress, and some conservatives don’t quite get that.”

That’s certainly true and a good point, but it’s better applied to Libya, where Obama didn’t even bother to ask for an AUMF for his war against Moammar Qaddafi. That adventure blew up in Obama’s face, almost literally when the terrorist networks it freed ended up sacking our consulate in Benghazi and killed four Americans, including the first US ambassador to be killed in the line of duty since the Carter administration. However, an AUMF is still a Congressional action, and Congress can revoke it any time, with much less political freight than with an outright declaration of war. Paul should stick with that, especially if he’s concerned about handing over too much power to an already autocratic Commander in Chief.