On Oct. 23, Sen. Rand Paul (R-Kentucky) gave a major address in front of the Center for National Interest, a "realist" foreign policy think tank founded by Richard Nixon. As he did in a similar February 2013 speech in front of the conservative Heritage Foundation, the libertarian-leaning presumptive 2016 GOP presidential candidate attempted to sell his foreign policy vision to fellow Republicans as being in the tradition of Ronald Reagan and Caspar Weinberger, representing a middle path between the near-absolute anti-intervention of his (unmentioned) father and the hyper-interventionism of the Washington establishment.

As has become routine for the high-profile junior senator from Kentucky, reaction to the speech varied widely depending on audience. Anti-tax crusader Grover Norquist, who has long advocated a less interventionist foreign policy, told reporters "I think I just heard Ronald Reagan speaking." The lefty analysis site Vox enthused that "Rand Paul just gave one of the most important foreign policy speeches in decades," because it "declared war on his own party." The Hill described the address as "anti-isolationist," neoconservative Washington Post writer Jennifer Rubin scoffed that Paul was "still pretending he's not an isolationist," and so on.

Of particular interest to libertarians looking to probe the senator's foreign policy principles was his seemingly dissonant support for U.S. air strikes against the Islamic State and opposition to intervening in the ongoing Syrian civil war. When Paul first backed hitting ISIS in early September, the national political press erupted in a spasm of articles accusing him of politically motivated flip-flopping, a charge the senator testily refutes.

Four days after this latest foreign policy speech, Reason Editor in Chief Matt Welch spoke with Sen. Paul over the telephone to flesh out his notion of realism, and probe some limiting principles on taking the nation to war.

reason: You mentioned in your speech that America shouldn't fight wars when there is no plan for victory. And you're still supporting airstrikes against ISIS. How do you visualize our plan for victory while doing airstrikes against ISIS?

Paul: I see the airstrikes really as defending vital American interests, and that would be our embassy in Baghdad as well as our consulate in Erbil. I've been very critical of Hillary Clinton over the last couple of years for her lack of defense for Benghazi. I do think that it is a function of our national defense and our foreign policy that when we do have embassies around the world, we do defend that presence.

reason: But then what would be the limiting factor on that? Because we have embassies all around the world, obviously, and bad things will happen from time to time. So how do you prevent that from being a reason to launch airstrikes anytime some random group of bad guys gets within 15 miles of a place that you control?

Paul: I think actually if you look at the world, you'll find very few of our embassies are actually under threat from war. There's probably a list of 20 that may have some threat. Then you narrow the list down, there's probably only I would think less than five. I would think Libya would have been one of those.

One of the reasons I fault Hillary Clinton is for not recognizing and understanding that Libya probably would have been either at the top of the list or in the top five most dangerous places to be in the world for an American diplomat. Right now probably top of the list would be our consulate in Erbil and our embassy in Baghdad. So I don't think that is a generalized warrant to go to war anytime. In fact, I've also said that the president should have made the case to the Congress and asked for authority to be involved in defense of these embassies and in defense of this consulate. He should have asked for permission from Congress the way the Constitution intends.

reason: What happened to that notion? In September 2013, when you were leading a ragtag army of bipartisan backbenchers against the president, something like 140 congressmen signed a letter saying you can't engage in airstrikes in Syria without coming to us first. What happened to those people and that movement?

Paul: I think there are still a lot of them there. I think, though, there are two sorts of issues. One issue is how you go to war. The other question is whether you go to war.

I think the how you go to war, that coalition is still out there, of people who believe in the Constitution, that Congress declares war. I think that principle actually is a very general principle that includes not only libertarians but conservatives as well.

The question on whether to go to war, I think as events have unfolded, or whether or not we have to have a response or a defense against ISIS, has changed as circumstances have changed. I think when Syria came up a year ago, there were people, myself included, who were loud voices against getting involved in that messy civil war because we felt like it would be counterproductive, and that you actually might enable and embolden ISIS and other radical jihadist groups in that war. I still maintain that.

My main reason for saying that we have to be involved now is that you have a group that is attacking and killing Americans—I think there is a reasonable threat of [them] attacking our embassy or consulate—and also that has frankly declared war on us. Their spokesmen have said that they will come when they are able and that they do consider that they're at war with us.

reason: Do you see the Islamic State as more dangerous and worthy of us coming up with a robust response than, say, you would have seen Al Qaeda or some of their offshoots three or four years ago? Is there a qualitative difference in the type of organization that they have, do you think?

Paul: I think it's hard to compare and contrast. The one thing that many writers have talked about with ISIS is that they control territory and they control munitions and they control access to money, to capital. So in some ways they have a greater degree of organization and ability to be a threat than others would. You could see how if there were a nation that were created called the Islamic State that it would be basically the breeding ground for barbarity. So I think you can make that argument.

You can make some of the argument that in 1998 bin Laden was already sowing, and that him training in Afghanistan was a threat even back into '98. But to give a qualitative or exact differentiation between the two, I don't know if that's helpful.

I think there's a pretty strong argument to be made that this group that took Mosul in a matter of hours, with Erbil not being that far away, that there is some threat to that. As they grow stronger, can we really with certainty believe that anyone is going to defend our embassy other than us in Baghdad? That's the sad state of things over there. For 10 years we were supporting the Iraqi people, supporting the government, giving them arms, training them, but I have my doubts as to whether they're going to show up on the day that ISIS comes rolling in to breach the walls of the embassy.

reason: That looks like to me like a Saigon 1975 situation, where we've poured in $26 billion just in military aid in Iraq to prop up the guys who gave the weapons to the bad guys. What do you look at as a nightmare scenario, of the things that could go horribly, horribly wrong in the Middle East if we don't reverse course or if things just don't get better?

Paul: Instead of looking at the nightmare scenario, I'd look at the opposite way: What can we do to try to prevent a nightmare scenario? I think there are several things.

One, I think that encouragement through diplomatic means or through withholding or advancing help to the Iraqi government is something that we ought to do. That would mean that it needs to be a government that is inclusive as well as an army that is inclusive. If they're an army of Shia, they're never taking back any of those cities and [ISIS] will continue to grow and it will basically be a divided Iraq. Maybe that is what ends up happening anyway. But the only chance for the national government to function is for it to be inclusive of Sunnis.

The other thing that could dramatically change the situation on the ground and lessen the risk of ISIS—to our consulate as well as to our embassy—would be to see if we could be part of facilitating a peace agreement between the Kurds and the Turks. The main thing that prevents the Turks from being involved—and they could be involved in a big way—is that they're not sure who they dislike worse; in fact, they probably dislike the Kurds worse than they dislike ISIS. So they're watching things unfold on their border because the people in those towns on the border have been fighting them for 70 years, trying to take Turkish land and make it into a Kurdish homeland. I think there is a possibility for there being a Kurdish homeland as part of Iraq. If that were to happen, and we were to support it, you might find that the Turkish Kurds would maybe be interested in a peace deal that would allow them, the Turks, to be more helpful.

None of this easy, but I think there is a role for America to be involved with trying to help find a negotiated end or settlement that involves people who live there doing more to try to fix the problem.

reason: You said a couple of different things which may very well be true, but might seem to be at least at some tension with one another. The two that stuck out at me were "the war on terror is not over" and we can't have "perpetual war." How do you square that circle, or how do you even visualize an approach that can contain both of those truisms?

Paul: Understanding that people over there dislike us for a variety of reasons. Sometimes they dislike us for our policy and our presence there. But sometimes they also dislike us just because they have an aberrant and bizarre notion of religion that hates people that are not part of the true religion. So, I think it is a combination of both.

I think [we also have to understand] that perpetual war is not going to win. The long war only wins when civilized Islam decides to stamp out this aberrant form. [Hernando] de Soto had an article in The Wall Street Journal a couple of weeks ago that we quoted from [in my speech]. In it he talked about the experience in Peru, where they did build up their military presence, they did recruit citizens to be involved in it, but they also recognized that the recruitment to the Shining Path [terrorist group] was often one where people were outside the economy because of government obstruction. So they made it much easier to incorporate people from the nonofficial marketplace into an official marketplace, meaning making it easier to get licenses, easier to sell your stuff on the corner. In doing that, he felt that there was a great deal of lessening of the impetus for people to join the Shining Path. I think [the reformers] have largely won that war.

He studied the problem in Egypt, and I like the way that he looked at the man who committed self-immolation in Tunisia. He wasn't a religious radical. He wasn't really looking so much for religious counterbalance; he was looking basically for economic freedom. [De Soto] mentioned how much off-the-books economy there is in Egypt because of the crony capitalism, that if you can get that as part of the official marketplace then the economy booms and things become more secure, title becomes more certain, and really the impetus for terrorism [recedes].

So there are other ways to fight other than perpetual war, is what I'm trying to say.

reason: How have your travels to the region, your term in office, even the process of running—or, I'm sorry, not running for president, just being a nationally prominent politician, how has that, if at all, altered your worldview about U.S. foreign policy?

Paul: Some of it is, four years ago I was an ophthalmologist practicing in a small town. So my worldview might have been a little more narrow at the time because I really wasn't thinking that an ophthalmologist had to have a foreign policy.

I've had some principles that I've had probably for a long time. They're principles that we should obey the law in foreign policy: that the Constitution is important, that our Founding Fathers were very explicit that it would be difficult to go to war and they would have to pass through Congress and that's a messy process, that it probably would be infrequent because you have to have consensus when it happens. That remains a steadfast belief.

The second part, though, is not the process of how it occurs, but the facts of it. I think that's something that good people can debate, but it involves facts and it involves presentation of whether or not something is in our national security interest or a vital American interest. I think that's where the real debate needs to occur. One is how you do it: the Congress should do it, not the president unilaterally. But then when you get to Congress, then it is a debate over the facts, and sometimes reasonable people might disagree on when exactly a vital American interest is broached.

But the thing that we should do is not just make a conclusion and not have a debate. I think probably too often in the past several decades politicians have simply said, "Oh, it's in our national interest." Well, that's a conclusion, and that skips the debate. Part of the reason to come into Congress and have the debate is that then there would be a full throated debate, hearing the facts, listening to it, discussing whether or not involvement in a region around the world is in our vital interest. But having skipped that step is a serious problem and I will continue to push when Congress comes back that it is our obligation, it is our role to vote on this. Although it seems a day late and a dollar short to do it four months after the campaign has commenced

reason: Shifting gears a little bit here, you've been digging deep in the well of George Kennan, and you've read enough of him by now to realize that George Kennan contained multitudes throughout a very long and storied career. He was a huge late-in-life critic of expanding NATO, which a lot of libertarians are against and for whatever reasons I am not. Do you agree with that bit of Kennanism? Do you think we expanded NATO too much?

Paul: There are two sides to the argument. One side says, well if you put them in NATO then Russia won't attack them because they'll know that we'll defend them. The other side says, you put them in NATO and you provoke the bear and you end up having more war. I think some of it depends on exactly what geography we're talking about.

We have included the Baltic nations, but we did not include Georgia or Ukraine, I think, because Georgia and Ukraine had historically been part of Russia for a long, long time. I think it was not advisable to put them into NATO, and at this point in time it is still not advisable. The Baltic nations are part of NATO, and I think that is what it is. We have to approach things from where we are, and not from where we want to be, because I think once people become part of NATO, there's not an undoing part of that process.

reason: Speaking of the world as it is, we are extended into any number of hundreds of bases and troop deployments in Korea and Japan and the usual litany that I don't need to bore us both with. To what extent, even as maintaining a very robust defense, to what extent can or should America withdraw some of its reach or just numbers in places that are relatively peaceful?

Paul: I think the world we live in, it is no longer probably as necessary to have large amounts of land troops in different places. Is it still necessary to have air bases and places to refuel and to have our presence out there as a force for open commerce? For example, since the beginning of the republic we thought there was a role for not letting pirates attack our ships. Is there a role for us around the world? I would say yes.

Over time, even without having a lot of libertarian influence, I think cost influences downsizing greatly. The number of folks that are stationed in Europe, I don't have the exact numbers, but it's considerably less than it was 20 years ago. I think there is definitely an argument to be made that we don't have to have hundreds of thousands of troops forward-deployed, but that we should have good relations with allies, good places to be at port with allies, and there will still be presences in certain places around the world.

But our goal should not be to be involved in every civil war around the world, but to actually try to be able to defend our interests without being drawn into every war.

reason: I'll end on politics. [In] 2007 it was basically Ron Paul versus nine uber-hawks; 2012, the field starts to look a little bit different, people questioning the Iraq war, at least a little bit. How do you assess the comparative broad strains of the foreign policy debate in the Republican Party heading into the 2016 election?

Paul: I think there are two audiences. The audience in Washington is basically in favor of involvement everywhere, all the time. At the top of both parties often they're for indiscriminate involvement, I think. But if you talk to the American people, in the Republican Party or the Democratic Party, I think you'll find that, even within the rank and file of the military, there's less enthusiasm for being involved in every civil war around the world, and that people out in the countryside recognize that we have problems here at home: that the economy is still struggling, that we have to defend the country and that we need strong leadership.

I think the vast majority of people are not for sending 50,000 troops back into Iraq at this point. But the vast majority is also for standing up and saying to barbarians that we're not going to let you behead our citizens. So I think it's a little bit of both. I think if you're looking at audiences, in Washington you'll find that there's an opinion that doesn't really reflect the American opinion that well.