To begin with, two notes about Latin. First, I’m not sure that “Yoo” is the proper declension of “Yoo.” I seek the help of all Latin-equipped NRO-readers.

Second, I think the more appropriate Latin to use here is “O tempora! O mores!” Because while I agree with much of what my friend Andy McCarthy says, I think that the understanding he outlines of the war power and of America’s interests is some distance from the Framers’ original vision.

But before going into our differences, let me make clear that Andy is right that not everyone who believes in more of a congressional role in approving military conflict is an isolationist, nor must every isolationist be someone who believes that presidential power in war must be narrowed. In the political debate, however, it seemed to me that the members of the House and the Senate (many of them newly elected or Tea Party supported) who were demanding congressional approval or a funding cutoff of the Libyan war were doing so because they wanted to limit American military action abroad. While I have a lot of sympathy for the Tea Party’s goals on domestic policy, I don’t think that its principles (if it can agree on them) mean that the United States has to bring a myopic accountant’s eyeshades to foreign policy. From my interactions with Tea Party members, I don’t think there is a settled view on foreign policy, so I think those in the House and Senate who wanted an authorization for Libya or tried to cut off funds for the war are mistaken on the Tea Party’s views.

I also agree with Andy that the Constitution permits the president to use force, without congressional consent, to prevent a direct attack on the United States and to protect American national security abroad. I think that we’ve been misled by the modern myth that Congress’s power to “declare war” is a shorthand for beginning military hostilities. The Framers fought a number of early wars without a declaration from Congress: conflicts with the Indians from 1789 on, the Quasi-War with France, the Barbary Wars. Of the wars fought under the Constitution during the lifetimes of the Framers themselves, only the War of 1812 received a declaration of war from Congress. In the 100 years before the Constitution, the British fought numerous wars, and they only declared war once before hostilities started — and it is from the British that we borrowed legal terms like “Commander-in-Chief,” “executive power,” and “declaration of war.”

Where Andy and I part ways, I think, is on whether the president can use force beyond the protection of the United States and its national security. Can the president use force abroad to achieve foreign policy interests that are not strictly necessary for the protection of the national security?

Presidents have, of course — starting not just with the Korean War, but with FDR’s pre-WWII efforts to help the British, Wilson’s expedition to Russia, and so on. I think those interventions are constitutional, stemming from the original understanding of the Constitution and early practice. The Constitution’s text doesn’t have the limiting principle in it — that wars can only be in self-defense (whether actual or anticipatory) unless declared by Congress. Again, Britain conducted many wars — most were for foreign policy goals, as their island status made self-defense less relevant — under similar constitutional terms at the time with no declarations of war. Some of our early American wars were undertaken, I think, to achieve foreign policy aim rather than protect national security. Jefferson’s early intervention, in the same region of the world as today, against the Barbary pirates was not necessary to protect our national security, but to expand US shipping in the Mediterranean (eerily similar to our goals today, in a way).

Also, how are we, not to mention the Constitution, to distinguish between national security and foreign policy? It seems to me that achieving regime change in Libya, and in other parts of the Middle East more broadly, could do more to help our national security than many other things we are doing these days. Victory in the Libyan War may have benefits that take longer to realize than a quick Predator strike in Pakistan, but it may also be broader, deeper, and longer lasting.

This brings up the second point, where I think Andy and I really disagree, and that is over the merits of the Libyan war, and the freedom agenda — if we want to call it that — more broadly. I don’t want to defend Obama’s mismanagement of the war by waiting until just before Benghazi was overrun to intervene, nor his submission to the United Nations for leadership. I’ve written elsewhere, at the time, that Obama should have intervened immediately to overthrow Qaddafi without waiting on the U.N.

But I think the Libyan intervention made a great deal of sense in the short and long runs. In the short run, we have rid the world of another awful dictator. We’ve removed Mullah Omar, Saddam Hussein, and now Qaddafi — that is without a doubt, to me, a great benefit to the United States and the world. We should have done more to push out the dictators in Tunisia and Egypt, and we should be doing a lot more to remove one of the real cancers in the Middle East, Assad in Syria. We will be advancing our interests by simply getting rid of these dictators. In the longer term, regime change in these places will do a lot to change the conditions that have allowed extremist Islamic jihadism — on which Andy has written so eloquently — to flourish. The Arab Spring may have been a knock-down blow to al-Qaeda, which is becoming irrelevant in its political appeal now that young Arabs can redirect their valid frustrations on their own regimes in a productive way.

And in the longest term, I hope for democracies in Afghanistan, Libya, Iraq, Egypt, and Syria, but I realize how difficult it is and how long it will take, and I don’t want the U.S. trying to turn all of these countries into little Jeffersonian Virginia’s. But if we can make them into democracies, the benefits for our national security could be enormous, beyond even draining the swamp that birthed al-Qaeda and radical Islamic terrorism. There is one empirical truth about international relations over the last two centuries, and that is that democracies do not attack each other. Political scientists themselves cannot agree on why, but if we can convert our former enemies into democracies, as we did after World War II, it would make those nations at least no longer hostile to, if not outright friends of, the United States.

— John Yoo is a law professor at the University of California, Berkeley, and co-editor of Confronting Terror: 9/11 and the Future of American National Security.