MS. DIANE REHMThanks for joining us. I'm Diane Rehm. French authorities continue to investigate Friday's terror attacks that killed more than 100 people in Paris. Today, U.S. war planes have joined French fighter jets bombing ISIS targets in Syria. And French officials now say they've identified the mastermind of the attacks.

MS. DIANE REHMHere to talk about the latest on the Paris attacks and the global response to a growing worldwide threat from ISIS, Bruce Hoffman of Georgetown University, Mark Mazzetti of the New York Times, William McCants of the Brookings Institution and joining us from a BBC studio in London, former U.S. Ambassador to NATO, Nicholas Burns of Harvard University. But first, joining us from Paris, Lauren Frayer. She's a reporter for NPR News.

MS. DIANE REHMLauren Frayer, news this morning that French police have identified the mastermind of these attacks. What do we know?

MS. LAUREN FRAYERWell, we know that the mastermind is a Belgian citizen who ordered the attacks. That's according to sources close to the investigation in Paris. So there was a French national on the ground organizing the attacks and they were ordered by someone higher up in ISIS, a Belgian national and both of those men are believed to be in Syria. On the ground, five of the seven assailants have been identified by French authorities. They've been identified by fingerprints.

MS. LAUREN FRAYERThey blew themselves up in a series of six attacks. The latest two we heard about today are both French nationals and all of them are either French or Belgian nationals so all men born in Europe, living in Europe legally, not recent arrivals, likely second generation immigrants. And they are all also believed to have spent time in Syria over the past few years.

REHMAnd Lauren, what about the eighth attack? What do we know about him and also three brothers who are said to have been involved in the attack?

FRAYERRight. So those three brothers, one of them is alleged to have been the so-called eighth attacker, the only man to have survived. And initially, French authorities had said that all the attackers were killed and Parisians sort of felt a sense of relief then that they could get on with their grieving. And then, yesterday, French authorities announced that they had found this car, a possible getaway vehicle, way east of Paris and so the discovery of that car far from the bodies of all of these suicide attackers lead authorities to believe that there is an eighth attacker who may have escaped.

FRAYERAnd so a manhunt has ensued. There have been raids in Belgium today, in one neighborhood of Brussels, to try to find that man. Unfortunately, the raid has ended and without apprehending him. But he's one of the three brothers that you mentioned.

REHMLauren, it's interesting. After the "Charlie Hebdo" attacks, there were large demonstrations. We're not seeing that this time. How come?

FRAYERIt's really been a muted response here. I mean, everything was closed over the weekend, monuments, museums, the Eiffel Tower even closed. Notre Dame was closed to tour groups. And so you had people sort of wandering the streets of Paris, taking snapshots of these impromptu memorials that have popped up on street corners where people were gunned down. There have been large gatherings in Parisian squares, people lighting candles, leaving condolence messages.

FRAYERAnd what's chilling -- in talking to Parisians, what they find chilling about this in contrast to the "Charlie Hebdo" attack is in the "Charlie Hebdo" attacks, and the attacks on the Jewish supermarket in January, those were specifically targeted groups, journalists or Jewish people. And this seems to have been completely random, that it was young people at a concert, that were people at a soccer game. And so Parisians really feel vulnerable, that it could've been them.

REHMFrench President Hollande has called what happened in Paris an act of war and the French air force is bombing targets in the ISIS capital of Raqqah. Do the French people support that kind of response?

FRAYERI mean, anecdotally, I've been on the streets talking to people. I don't have polling data, but I think people feel pretty fierce about that. The interior minister went on television today and said anyone who attacks France, French will take that fight to them. And I've been talking to people on the streets who support those air strikes in Syria. They're coming together. They're trying to feel united and trying to feel French and grieve together, but at the same time, they're angry.

REHMLauren Frayer, a reporter for NPR News joining us from Paris. Thank you so much, Lauren.

FRAYERGood to be with you, Diane.

REHMAll right. And turning to you, Mark Mazzetti, this idea of an act of war expressed by the French president, what does that actually mean not only for France, but for the world at large?

MR. MARK MAZZETTIWell, for France, you saw the beginning of it last night with the attacks into Syria, of course. They'd done military strikes before, but this is very clear indication that the French government is going to respond to this attack fairly relentlessly. I think the idea of an act of war, saying it that way is interesting. It sort of conveys that the French very much see the Islamic State as something of a foreign entity, a foreign, you know, not just a network, but a group that has territory, that has territory that can be attacked, that this is, in many ways, how ISIS deploys its troops abroad to do attacks like in Paris.

MR. MARK MAZZETTIAnd the response will be in a military style. So I thought that is somewhat significant in terms of the language.

REHMBruce Hoffman, you recently wrote a piece titled "ISIL Is Winning." Talk about what you mean.

MR. BRUCE HOFFMANWell, ISIL, unfortunately, has adapted to, and adjusted even, to some of our most consequential countermeasures. For example, the planners behind the Paris attack in past are believed to have operated out of Turkey and Greece, not in Syria, which is being bombed, in other words, in place that they believe are safe havens. So you've got a group that is not just local, has already plotted in recent months at least seven attacks in the United Kingdom, one in Australia, over the July 4th holiday in the United States, arrests in the Balkans and in Switzerland.

MR. BRUCE HOFFMANSo what we see in recent months is them flexing their muscles and spreading their wings, as it were, and planning to operate further afield, but doing so not exclusively from Syria.

REHMAnd Will McCants, has the U.S. done enough in order to track what ISIL is doing and if so, why was it not aware of the attacks coming in Paris?

MR. WILLIAM MCCANTSWell, according to reports from anonymous security officials, the United State apparently did alert the French in September that there was a plot afoot to go after some targets inside of France, but they didn't have a lot of specifics. I think the truth is, for many security services and intelligence agencies, including our own, the Islamic State is so widespread and, as Bruce said, operating in so many different countries and it has so many foreign fighters who are returning back home that it's very difficult to keep track of all of them and it places a great strain on our intelligence apparatus.

REHMAnd this morning, we hear that even Washington has been specifically mentioned by ISIL?

MCCANTSThat's true. There's a new video out threatening attacks against Washington, D.C., but they make those threats regularly so it's not necessarily indicative of an actual plot afoot.

REHMIs Washington, is President Obama doing enough here, Bruce Hoffman?

HOFFMANWell, the problem with the bombing is it does weaken and it certainly hurts ISIS, but if they have terrorist cells and command structures set up in other countries, it doesn't mean that the types of attacks that we saw in Paris or indeed the July 4th plots directed against the United States are necessarily going to be impacted. I think what's interesting is that ISIS, in the past week, has been able to target at least three of what it sees as its main enemies in three different places.

HOFFMANThe Russians, of course, with the downing of the charter plane over the Sinai, the attack in Lebanon against Hezbollah and the Shia and then, they round that off the same day with the attacks in Paris.

REHMAnd this morning, as President Obama spoke, he was asked whether the U.S. should send U.S. ground troops to the region. He responded, that would be a mistake. How do you respond?

HOFFMANI've never seen, in history, a counterterrorist campaign that's succeeded only through the use of air power. I think it depends how we send our troops is more important than whether we send them or not. I think troops that are embedded with indigenous forces that could act as target designators and spotters for our air power would probably result in a higher level of attrition and greater targeted damage against ISIS, but at the end of the day, though, you can't fight terrorism from 30,000 feet up.

REHMSo what are you saying? We need many, many troops embedded there?

HOFFMANNo, I wouldn't say many, many. I think we need to avoid the same mistakes we made a decade plus ago, of having large numbers and I think we can learn from that and function differently. But first and foremost, the most credible force against ISIS are the Kurds and we haven't really been doing enough to back them.

REHMBruce Hoffman, director of the Center For Security Studies at Georgetown University. Short break. Your calls when we come back. Stay with us.

REHMAnd welcome back as we talk about the attacks in Paris by ISIL that have killed nearly 130 people, many more injured. Here in the studio, Will McCants, he's with the Brookings Institution. Mark Mazzetti is with The New York Times. Bruce Hoffman is at the Center for Security Studies at Georgetown University. And joining us now by ISDN from the BBC Studios in London England is Ambassador Nick Burns. Ambassador Burns, the whole question of NATO and whether NATO comes into a response to the Paris attacks, what is your thinking in that regard?

AMB. NICHOLAS BURNSWell, Diane, one of the options that the French have is to invoke Article 5 of the NATO Treaty. It's only been invoked once in history, that was the morning of September 12, 2001, after the attacks of 9/11. I was the American ambassador at NATO at the time. You need -- NATO acts by consensus, so every country in NATO -- and there are now 28 members -- would have to agree. The French have historically been ambivalent about NATO. De Gaulle actually kicked NATO out of France in 1966. I think the French, for that reason, and also because they want to make sure that there's a unified response, will be -- they'll be leery of invoking NATO at this time.

AMB. NICHOLAS BURNSBut I think, Diane, if I could just say, the contradiction that all of us are dealing with is that for the last year and a half, the United States and other countries have been saying, we're going to defeat ISIS. But we haven't had a defeat strategy in place. We've had a contain strategy in place. Secretary Clinton, Hillary Clinton, mentioned it in the Democratic debate on Saturday night. It's not going to be enough to contain them. We have to defeat them.

AMB. NICHOLAS BURNSBut as Bruce has just said, you can't defeat them by air. And so now what the administration, the French, the Arabs have to do is reinforce the Peshmerga, the Kurdish forces, the Syrian Kurds and the Sunni Arab groups by conventional means, reconstitute the Iraqi Army. That's the only way to defeat ISIS and that's a long-term proposition. So I think that's the problem that President Obama is facing.

REHMHow do you respond, Will McCants, on the idea of containment rather than defeat?

MCCANTSThe Obama administration has been pursuing a containment strategy. And whether it is willing to admit it or not, is treating the Islamic State in Syria and Iraq as a state, which it is. But I think we're selling the current strategy a little bit too short. I mean, over the past year, the allies have been able to take away 25 percent of the Islamic State's territory. That's not insignificant. And I think it's one big reason why the Islamic State has shifted to international, coordinated attacks on its enemies because it is losing strength.

REHMBruce Hoffman.

HOFFMANNo, I disagree. I don't think that the loss of territory really fundamentally alters, I think, ISIL's -- ISIS's ambitions or really degrades its capabilities. ISIS has become almost a hybrid force. It's both a conventional army -- and that is being weakened a bit on the ground -- but it's still also an insurgent force and also, as we saw in Paris, a terrorism strike unit. And it's the latter one that's going to impact us the most and impact our allies in the West the most.

REHMIt's interesting to me that the president was asked about whether he felt that we had given sufficient -- says his intelligent threat reports contain no specific mentioned in advance of attacks on Paris that the U.S. could have done anything about. Bruce Hoffman.

HOFFMANI had heard reports, too, that Iraqi intelligence had provided reports directly to the French. But I think a lack of specificity -- since January, France knows that it's been an intense risk. I think it was hoping against hope that the next attack would not be something along the lines of this Mumbai-style, running gun battles and suicide attacks. These are the most challenging types of assaults for law enforcement to counter and for intelligence to anticipate, especially when you have very porous borders and when you have trained operatives, I mean, people who are battle hardened and who also function and respond to command and control, that are able to operate in a disciplined fashion.

REHMMark Mazzetti, how good is our intelligence?

MAZZETTIWell, it seems that good enough to be able to detect that there was some kind of a threat coming, there was an attack looming, that Paris is a -- or that France might be a target. But obviously not good enough and not specific enough, not only from the U.S. side but on the rest of European intelligence agencies, to be able to thwart it. I mean, this is the problem that the United States and other countries face, is being able to get the specific intelligence. And I think that, you know, as much as people might want to say this is a highly sophisticated attack, in the sense that it was coordinated, at the -- the other side of the coin is that it was not that difficult to do, right?

MAZZETTIYou have groups of people who are willing to die and they have enough manpower and access to guns to be able to carry it out and to attack a theater, to attack cafes. This is not that difficult to do and why it might be easily replicable. So to the intelligence question, in order to thwart that attack, you need to have penetrated that specific cell, the specific communications and be able to do it in time.

REHMSo how much more intelligence do we have to have to begin to identify and stop these kinds of attacks before they occur, Will McCants?

MCCANTSWe need a lot more human intelligence. And the fact is, the Islamic State is very difficult to penetrate, particularly since they hold territory. There are reports that a number of these attackers are also using sophisticated encryption, which is also hiding their movements. And they're using a number of low-tech ways to communicate. Like the rest of us, they have watched the news and seem the revelations about government capabilities on eavesdropping and they have reacted accordingly. They're very careful in their operational security, which is why they're able to penetrate and carry out an attack like this.

REHMSo what is the key here, Bruce Hoffman? Is it more intelligence, better intelligence? What's holding us back?

HOFFMANWell, I think one of the main problems is that this threat has grown enormously in a relatively short period of time, at exactly a moment when our resources are contracting. Intelligence resources are at least static, if not having declined over the past decade. So we're asking intelligence -- and it's not just the United States, it's across Europe -- so we asking police forces, intelligence and security agencies to do more, to track exponentially more people than before, not just local, radicalized individuals but foreign fighters, people leaving, but also people coming back.

HOFFMANAnd the fact of the matter is that they're overwhelmed. I mean this is one reason, I think, that many people are suggesting, in the aftermath of the Paris attacks, we've got to go to the source of ISIS. That's the only way to stop this.

REHMNick Burns, would you agree?

BURNSWell, I do. And I think that one thing the United States can do here is we've got enormous political reach. We can be the coalition builder of a stronger Turkish, European and Arab coalition that needs to do many things at once: better intelligence cooperation, closer law enforcement and judicial cooperation, financial cooperation to try to interdict ISIS funding, and of course military. And military really is not probably the first instrument. You've got to have those other instruments in place. The problem we've got right now, the Turks aren't cooperating. They're bombing the Syrian Kurds whom we're supporting.

BURNSThe United Kingdom is not even flying -- conducting airstrikes into Syria because their parliament hasn't given approval. And the Arab countries, the countries that have the most at stake -- the United Arab Emirates, Saudi Arabia, Kuwait -- they're kind of missing in action in the fight against the Islamic State.

REHMNick Burns, what do we know about the conversation that took place between President Obama and Russian President Putin at the Turkish event?

BURNSWe know they met yesterday for 30 minutes. Of course they were photographed meeting together with their close advisers. What they're focused on right now -- what the Russians are focused on with John Kerry, Secretary Kerry -- is trying to start a diplomatic process that we haven't talked about yet. How will this war end? Like most modern wars, at some point it will end at a negotiating table in Vienna or Geneva. Getting there, it's going to be extraordinarily difficult.

BURNSThe Russians, of course, what to preserve President Assad of Syria in office. Eventually the United States and the Arab countries want to see him gone. I think that Secretary Kerry is right to start this. But the Russians are difficult partners, indeed, because they promise a lot, they very rarely deliver.

REHMAnd what do you think about diplomatic efforts? Bruce Hoffman.

HOFFMANWell, eventually, I agree, precisely with Ambassador Burns. Eventually that's where we'll be. But I reorder his priorities. I think, at this stage, it's got to start with military. Without fundamentally weakening ISIS, without diminishing its allure and attraction, without really degrading its command and control, we're not going to make progress on other fronts.

REHMMark.

MAZZETTILet me just add on that there are different priorities among the different players. We talk about the United States and Russia. Now Russia has gone to war in Syria with the stated purpose of going after ISIS. What has actually happened in the month or so since it happened -- two months -- is that they've had far more strikes against rebels who are aligned against Bashar Assad, who are pro-United States, even trained by the CIA. Then there have been strikes against ISIS. So we should all be very open about the fact that not everyone has the exact same agenda here.

REHMBut do you think that might change in the wake of what's happened in Paris? Bruce.

HOFFMANIt's moved a little bit more in that direction. But I agree with Mark, I mean, the -- and Ambassador Burns, the common will and this common perception of what needs to be done just doesn't exist yet.

REHMSo when you talk about more force, what exactly are you suggesting?

HOFFMANWell, again, backing what I think is the only credible U.S. ally that's demonstrated any ability to push back ISIS, which is the Kurds -- both the Peshmerga and the YPG, the People's Protection Units. And there has been support to them, but an intensification and acceleration of that support. Similarly, I think more support to the Iraqi Security Forces. They can't do it on their own. And I think the worst thing is allowing the Shia militias to fill that vacuum. But again, that means not huge numbers of troops, but a deeper involvement than just advisers in the background.

REHMWell, explain the difference and talk about realistically what you mean.

HOFFMANEmbedded in helping to command the indigenous forces. Also acting as aviation targeters, to make sure that our munitions are being very specifically targeted where they will have the most effect. Those are two capabilities that don't exist now.

REHMSo how many people are you talking about?

HOFFMANWell, again, low numbers but people that aren't necessarily in the background. And unfortunately, the possibility arises -- as we saw in that raid to free Kurdish Peshmerga hostages two weeks ago where U.S. commandos participated, there would be the risk of casualties. But what we're doing to date is not working.

REHMWill McCants.

MCCANTSI would say it is working. It's very slow but, if we go any faster, if we send in a large number of troops and remove ISIS -- which we could -- we may have what a colleague of mine calls a catastrophic success. What do we do with all of this new territory, given the widespread dysfunction. I think the go-it-slow approach has been working and gives us time to reabsorb these newly liberated areas. And as Bruce is saying, this effort to work with the Kurds, particularly to push down into ISIS headquarters in the City of Raqqah, in Syria, I think is bearing some fruit and deserves reinforcement.

REHMAnd you're listening to "The Diane Rehm Show." Ambassador Burns, I know you wanted to jump in.

BURNSI just wanted to say, I think Bruce has made a very strong point, that to be successful ultimately in ending the war, we're going to have to impose greater military pressure on the Islamic State and the Syrian government. Here's a big strategic problem: this war is widening. It's metastasizing into Lebanon and to Iraq and to Turkey and Jordan, and now into Europe, with this flow of refugees. And if we don't do something to turn around a policy that hasn't been working, we could have a bigger problem on our hands a year or two from now.

REHMFrench President Hollande has just spoken. He says, we're fighting a war against jihadist terrorism that threatens the whole world, not just France. How do you react to that, Bruce Hoffman?

HOFFMANWell, certainly I think ISIS has a very similar ideology to al-Qaida, which was not just local and regional struggles but raging war against what they defined as Islam's enemies and waging war wherever it was necessary. So it's certainly not -- and we're seeing that more and more clearly -- the local or regional phenomena that we once thought or once wished it was.

REHMAll right. Let's open the phones now. First to James. He's in Benton Harbor, Mich. Good morning, you're on the air.

JAMESGood morning, Diane. Thank you for taking my call.

REHMCertainly.

JAMESI have a question regarding the Syrian refugees. How do we continue to act as a compassionate nation and still keep this country safe from these embedded ISIL terrorists that seem to be coming across with the legitimate refugees.

REHMAmbassador Burns.

BURNSWell, President Obama just spoke to this question about an hour ago in his press conference and I thought he made a very effective statement. He said, if we slam the door shut to Syrian refugees, it will be a betrayal of our values. That was his quote. Since the end of the Second World War, in every refugee crisis, the United States normally takes about half of the refugees, given the size of our economy and country. In this case, Germany will end up taking close to a million people. We're only committed to take 10,000 Syrian refugees. Frankly, I think we should do a lot more. 65,000 is what the United Nations is asking us to do. We will properly vet for security reasons every single refugee, of course.

BURNSBut our tradition is to keep our doors open, not to dig a moat around the country and pull up the drawbridges. And that's what some of the presidential candidates, frankly -- including Donald Trump -- have been saying, I think in the most incorrect and unwise way, over the last few days.

REHMThere are a great many people worried about whether ISIS will strike this country. What do you think the likelihood may be? Bruce Hoffman.

HOFFMANWell, they already have. I mean, the July 4th plot, which was organized by two leading British members of ISIS, who fortunately will killed in August and that derailed it, but that was a serious plot to attempt a strike in the United States. And it's not just a problem in the U.S. Canada, for example, has a tenth of America's population, but has sent at least as many if not more foreign fighters overseas. Canada has very different surveillance laws than the United States. It's intelligence agencies have very different powers, much more restricted than the United States. So it's a threat that's not only indigenous to the U.S., but it comes from even the northern border while a lot of attention is often focused on the more poor southern border.

REHMHow do you believe our intelligence capacity can be strengthened to make sure that an attack does not occur?

HOFFMANWell, this is certainly a threat that's well known to both Canadian and U.S. authorities and is being monitored. And the FBI, of course, in recent years has been moving more and more towards becoming an intelligence-oriented organization. But it's got to keep moving fast.

REHMBruce Hoffman, he's with the Center for Security Studies at Georgetown University. Short break, more of your calls, comments, when we come back. Stay with us.

REHMAs we talk about the attacks in Paris just before the break, we were focusing on the intelligence that the US is getting, how significant it is, and what it can do in order to interrupt any kind of threat or really pending threat to the US or elsewhere. Mark Mazzetti, you have been focused on the intelligence that, in fact, the President himself is getting. Tell us about that.

MAZZETTIWell, certainly, from President Obama's statements over the last year or so, he has not given a very -- a completely rosy picture of the progress of the war. He's been measured, but there are disputes inside the intelligence community about whether different agencies are, you know, burying some of the real truth about the campaign. Specifically, we've been writing about US Central Command, which is the military headquarters down in Tampa, which is running the war.

MAZZETTIAnd there's a whole cadre of analysts who believe that their assessments, which are fairly sober about how little progress has been made thus far in the military campaign had basically been buried by their superiors when they send reports up the chain of command.

REHMWhy?

MAZZETTIIt's a good question. We're still looking into it. There are various theories about why that might be happening, but right now, the DOD, the Pentagon Inspector General, is investigating this very incident about why the intelligence shop at CENTCOM, which is sprawling, 1500 people, why the most seasoned analysts doing this might not be having their views well known. Now, this is just one stream of intelligence that would get to the President, but is quite significant, because it's the military campaign, sorry, the military headquarters running the campaign in Iraq and Syria.

REHMGive me an example of something that might have been softened or not sent directly.

MAZZETTIWell, one example we've heard about is the assessment among analysts that the strikes on the oil infrastructure that ISIS has in Iraq and Syria, that what got reported up the chain of command to Washington, was that these strikes are having an effect on the money that ISIS can raise, on their overall ability to sell oil on the black market. When actually, the analysts were making assessments that they were quickly regenerating these, in sort of jerry rigged systems to be able to refine the oil to get it onto the black market. So, in other words, the strikes were having very little long term impact.

REHMSo, if in fact there is a fragment of truth to what you're saying, is the President being deliberately misled, or is there some mush on the ground here?

MAZZETTII think there's a good deal of mush on the ground in terms of, you know, different agencies are assessing different things. I think the CIA, the Defense Intelligence Agency as well, have a pretty sober assessment about how little, actually, the strikes have done in the past year or so in diminishing ISIS's capabilities. Now, you know, CENTCOM might have a different view. But ultimately, there's this question of if you are killing 5,000, 10,000 people, what does that mean if they can then regenerate and if you say you've killed 10,000 people over the last year and then your intelligence estimate says there are 20,000 fighters.

MAZZETTIWhich is the exact same you had a year ago, what does that say about the state of the campaign?

REHMWill McCants.

MCCANTSYeah, a lot of the reworked assessments have to do with the performance of the Iraqi military. I spoke with one of these defense analysis analysts a few weeks ago and he was telling me that the analysts described the Iraqi army fleeing on the battlefield, retreating. That language was changed higher up to redeploy. It's this mush that you're talking about. They're trying to soften the problems that they are seeing on the ground.

REHMBruce Hoffman.

HOFFMANWell, last April, I was at a conference at the US military academy at West Point, including senior generals, people from the intelligence community, academicians, human rights workers, and then GO representatives. It was astonishing. When the question was -- when the question was asked, are we losing the war against ISIS, 97 percent said that we were. Which goes completely against some of the rosier intelligence assessments that Mark and Will just described.

REHMThat does not make people feel very secure and one wonders what the end result is here or the effort on the part of the administration to say we are being kept safe verses what the generals are saying.

HOFFMANWell, it depends. If you have a containment strategy, you can believe that it's being contained until you have tragedies such as Paris. But the containment is not the same as destroying and dismantling and defeating an enemy.

REHMAmbassador Burns, do you want to comment?

BURNSWell, I think the major policy here is the President of the United States, President Obama. And he has -- he's operating under the ancient medical maxim, do no harm. And that is a -- that's a practical and understandable reaction to a turbulent, violent region. The problem is, if you pull back too much on US leadership, if the US is not playing its traditional role, then you have the current situation where Qatar and Turkey and Saudi Arabia are going in different directions.

BURNSThere's no central core leadership. That's the most important role politically, militarily, and intelligence that the United States needs to play. I hope that as a result of the Paris talks, the President will be convinced, he needs to step more into that political leadership role. He made clear in Turkey, over the last 48 hours, he will not put American ground troops, combat troops, into Syria and Iraq. I think he's right about that. But we're seeing an absence of the traditional American role, which I think has reduced the effectiveness of this international coalition.

REHMBruce Hoffman, do you think the President is right in repeating no troops on the ground?

HOFFMANWell, I won't second guess the President, but I will say, at least historically, incrementalism, or a graduated escalation against terrorist groups does not work. Rather, it's locked the terrorist group's enemy, ourselves, into a tit for tat struggle, that against our intentions, against our will, continues to spiral upwards.

REHMWill McCants.

MCCANTSWell, let's also recognize that this conflict extends far beyond Syria and Iraq. I mean, we may take the fight to Islamic State headquarters, but they have a significant presence in Libya. Their branch in Egypt took down a Russian airliner. This goes far beyond Mesopotamia.

REHMAll right. Let's go now to Jule in Johnson City, Tennessee. You're on the air.

JULEYes, two questions. Is Al Qaeda still wreaking havoc on the people there in the Middle East? And also, why is the United Nations not taking a more active role, you know?

REHMAll right.

MAZZETTIWell, that's the even worse news, that our preoccupation with ISIS this morning hasn't touched upon. Is that, at least in my estimation, Al Qaeda is regrouping and re-organizing. In fact, Al Qaeda's living large. They're letting ISIS take all the heat while they very patiently and quietly rebuild in Afghanistan. As they deploy their forces, such as the Khorason Group to Syria. And as, in fact, even worse, I mean, we call it the Nusra Front, the Support Front. We don't use the term Al Qaeda any longer, so what's happening, just as Will described, is this lack of agreement among our allies.

MAZZETTIQataris, Turks, Saudis, see Nusra not necessarily as Al Qaeda, but as a more moderate alternative to the heinous ISIS.

REHMAnd we have several emails, like this one from James. How do you vet Syrian refugees without documents? How do we prevent infiltration by ISIS fighters? Will.

MCCANTSWell, it's a real security concern, and I don't think it should be downplayed by anyone. It's a problem. And people, you know, with different political views will be quick to charge racism, but political leaders, necessarily, have to be worried about these problems.

REHMAnd Mark Mazzetti.

MAZZETTIIt's a nightmare scenario if you look at the European situation right now. You have, you know, thousands and thousands of refugees coming in to Greece and other places. And it is extraordinarily difficult to vet them. It's a politically charged environment, already, on the immigration issue. And now, into that charged environment, you have this deadly attack. And it's presumably, going to empower forces of retrenchment, those who want to close the borders, kick all the refugees out.

MAZZETTIAs Ambassador Burns mentioned, even in our own country, right, you have -- this is now becoming something that the political candidates are talking about. The plan to relocate Syrian refugees in various states in the United States. You're hearing all the local politicians, governors, senators, are saying, you know, not in my backyard. Not in our state, and so, so this is what happens. And you can't divorce politics from it, unfortunately.

REHMBruce.

HOFFMANI was just at Zaatari refugee camp in northern Jordan two weeks ago, the largest in that country. And the situation is absolutely heart rending, especially since getting colder. And I think about the Iraqi refugees that we brought into the United States, at least to my knowledge, only two were ever implicated in any terrorist plots. This was a minor incident in Bowling Green, Kentucky, that the FBI, fortunately, because of the attention they were paying to this, immediately stomped on and undermined.

HOFFMANSo, it's not as if that we have, you know, a huge track record of having brought in lots of Iraqi refugees or even Afghan refugees, Somali refugees, and seen lots of terrorism erupting from them in this country.

REHMNick, I know you talked about America's openness, its willingness to accept those in need. But what about that question? Those who want to come here without accurate documentation. Who do we let in? Who do we say, you cannot come to.

BURNSWell, Will's right that we need to take the security issue very seriously, given the situation. But we have a lot of history with this. We have more refugees in the world today than any time since the summer of 1945. For 70 years, we've been processing people from all around the world. We do not take people in if we don't know who they are. And certainly now, there'll have to be an FBI background check on people. This takes time, but we can keep the doors open.

BURNSWe have always done this, throughout every war, every conflict around the world. And so, I don't think this is an impossible task for our country. In fact, it's in the best American tradition.

REHMDo you believe that we can keep the doors open, Bruce?

HOFFMANI think we have to. We have desperate refugees in Jordan, for example, that are leaving Jordan to go through Jabhat Al-Nusra territory, Assad territory, ISIS territory, to reach Turkey simply because they're cold and they're hungry. And that's how desperate they are, so we have to be this compassionate.

REHMWell, and we have a question, why do Western nations, no, why is it that Westerners feel there is more of a refuge in ISIS than the nations they grew up in? Does that make sense? Maybe I'm reading this wrong. I think we'll move on and take a caller in Orlando, Florida. Nabil, you're on the air.

NABILHi, thanks for taking my call.

REHMSure.

NABILI think the biggest problem right now, that I see, is a narrative that's being portrayed on mainstream media. That, to me, is the greatest threat ever. And I'll explain to you why. Not one time has Fox, CNN or anybody else in the mainstream media ever once mentioned that ISIL is an enemy of Muslims more than it is the West. More Muslims get killed by ISIL, or ISIS, whatever you want to call those gang thugs, than any other victim. I'm Muslim, and there's not a single one value that they represent that's compatible with Islam, period.

REHMAll right. And you're listening to "The Diane Rehm Show." Nick Burns, do you want to respond?

BURNSWell, I think it's true. And Will McCants will have a lot to say about this, given his recent book, that the Islamic State is focused on combating Shia Muslims. And they have killed many more Muslims in both Syria and Iraq and now in Libya and other places than Westerners. This is a battle that all of us need to fight, that unites us with Muslims. It's not a war against Islam. We're trying to help the Muslims rid themselves of this cancer.

REHMThat's what Hillary Clinton said the other night during the debate, that it was not a war against Islam as a whole.

MCCANTSThat's right. Ambassador Burns is correct. ISIS has an enemies list as long as the roll call at the United Nations. It's not only against infidels, it's also against other Muslims who it brands apostates for not bending the knee to its rule.

REHMDo you agree?

HOFFMANYes, I mean, they've cast their net wide. I think one of their worst depredations is that they've made the Sunnis complicit in their atrocities, at least the Sunnis in territory that they control. In other words, they now fear, if a Shia or a Kurdish force comes and pushes ISIS aside, that they'll be subject to retribution. So they are very much victimizing their own people, of that there's absolutely no doubt.

REHMMark.

MAZZETTIAnd just one other point on this. You know, it should be pointed out that that's the reason why you see Iran very actively engaged in Iraq, trying to combat ISIS. They are very, very worried about -- Iran, of course, is a Shia nation, very worried about ISIS and their ideology. And so, that's why you see, in a way, you know, the United States and Iran are sort of working together in Iraq to combat ISIS.

REHMAnd one last email from John. How are these terrorists getting the weapons in these countries? Bruce.

HOFFMANOh my gosh, they've unfortunately seized, you know, at least 50 billion dollars worth of weapons that the United States provided to the Iraqi security forces.

REHMAnd left behind.

HOFFMANAnd left behind. Or that they took from the arsenal of the Assad regime. So, they have enough weaponry, according to some estimates, to outfit at least 300,000 fighters.

MAZZETTIAnd on the issue of how could the Paris attackers have gotten the weapons? Where would those have come from? I just wanted to note that this morning, John Brennan, the CIA Director, gave a speech and was asked about that and he discussed the smuggling networks, the black market networks, the Russian networks and others that are available, that would be available to people who might want to arm themselves for these kinds of attacks.

REHMWill.

MCCANTSThat's right. Belgium is known as a hub of illegal arms traffic. And a number of these attackers were based in Belgium, so it's no accident that they were able to get their hands on small arms.

REHMAnd one final quote from President Hollande, who said, terrorism will not destroy the Republic as it is the Republic that will destroy terrorism. He ended by saying, long live France. And indeed, we'll end our program with those words. Thanks to Bruce Hoffman of Georgetown University, Mark Mazzetti of the New York Times, Will McCants of the Brookings Institution. And Nicholas Burns, Politics Professor at Harvard University's Kennedy School of Government. Thank you all.

MAZZETTIThank you.

MCCANTSThank you.

HOFFMANThank you.

REHMAnd thanks all for listening. I'm Diane Rehm.