The Paris Response: Answering Urgent Questions in the Anti-ISIS Fight

• What is the mindset of ISIS leaders?
• Are the Gulf States stopping private support to ISIS?
• What are France's North African allies doing about the ISIS problem?
• Why isn't Turkey curbing the flow of Syrian refugees and ISIS returnees into Europe?
• How can Washington bring its Arab allies back into the fight against ISIS?
• Are many thousands of U.S. boots on the ground the only way to defeat ISIS?
• Why has ISIS been able to establish and maintain control in eastern Syria?
• Does ISIS threaten Israel?
• How should Washington respond to its allies' need for leadership?
• How can a highly adaptive and ruthless enemy like ISIS be stopped?
• What impact will the Paris attacks have on other Sunni and jihadist groups?
• How does ISIS finance itself?
• Why didn't France call NATO for assistance?
• How could the U.S. military effort against ISIS be made more effective?
• How much can the Kurds do against ISIS?
• Why is Turkey staying out of the anti-ISIS fight, and how can Washington persuade it to be more helpful?
• Does ISIS truly want to create an Islamic State, and would it leave the West alone if the West left it alone?
• What happens if Europe turns up the heat on Syrian refugees?
• How useful is Russia in combating ISIS?

What is the mindset of ISIS leaders?

Why blow up a Russian airliner and thus challenge a powerful nation to destroy you? Why murder innocent civilians in Paris in plain sight, thereby demonizing yourself and your faith and losing global support for your cause, whatever it is? Why behead a Chinese citizen and thus add one more powerful nation to the list of your deadly enemies? Why broadcast threats of imminent attacks against the United States, the most powerful nation in the world? Why infiltrate refugees fleeing from your terror in order to antagonize host nations against them? And what exactly does ISIS expect to happen when some or all of these actors come gunning for it in Syria and Iraq?

To answer these questions, one must understand the Islamic State's mindset: namely, its belief that creating global mayhem, fear, and chaos will bring about the end of days. To them, this is Armageddon, the last battle fought against infidels from different corners of the world. In that sense, their goal goes far beyond that of al-Qaeda and the late Osama bin Laden, who wanted just a limited war aimed at liberating Muslim nations from supposed U.S. imperialist hegemony. ISIS leaders have a wider vision and a more comprehensive strategic design. Their mindset can be boiled down fairly bluntly: "You want a clash with Islam, we'll give you a clash with Islam." Indeed, their nihilistic ideology and actions are based on a series of such fallacies -- that ISIS speaks for Islam; that Islam is a religion of conquest rather than peace; that those who die fighting for the sake of God and Islam are martyrs destined to live among the prophets in heaven; that Christians and Jews have lost favor with God; that its infidel enemies are cowards; and that its cadres are unlimited in number and global in reach. Perhaps most important, ISIS believes that it represents the "good" in this "final battle between good and evil," and that it will be victorious despite the seemingly insurmountable forces arraying against it.

— Mohammed Dajani

Are the Gulf States stopping private support to ISIS?

Over the past year, Saudi Arabia has suffered a deadly succession of high-profile attacks linked to ISIS. In June, Kuwait was victim to an ISIS suicide bombing at a Shiite mosque -- its worst terrorist incident in decades. And Bahrain recently announced its first trial of alleged ISIS supporters plotting attacks on the island. Deep concerns about these and other terrorist activities have driven policies aimed at discouraging ties between Gulf citizens and foreign residents on the one hand, and ISIS members in Syria and Iraq on the other. The idea has been to reduce the incidence of residents with ISIS links bringing the fight home to the Gulf states.

Funding and delivering weaponry to ISIS, traveling abroad to fight with the group, and providing other kinds of support is prohibited in most Gulf states. Several countries have been arresting, prosecuting, and jailing ISIS backers. In Saudi Arabia, ISIS financiers, would-be fighters, and clerics championing the group have been among the thousands of individuals detained by authorities in recent years. But some Gulf states are balancing other domestic and foreign interests with the extremist threat. One country that is understood to be home to ISIS supporters but has not announced a trial for anyone backing the group or other al-Qaeda-related entities is Qatar.

Most Gulf states have not taken serious steps to curtail the extremist dogma on which ISIS feeds and grows. They continue to tolerate and in some cases sanction hateful ideology in their mosques, schools, and/or media. Oman and the United Arab Emirates have been relative exceptions in this regard. Gulf efforts to halt private support for ISIS in Syria will continue to be challenged by this cyclical phenomenon.

— Lori Plotkin Boghardt

What are France's North African allies doing about the ISIS problem?

Among the nations eagerly awaiting clarification on France and Washington's response to the Paris attacks are Morocco and Tunisia, their closest allies in North Africa. The attacks and the broader ISIS menace resonate deeply with both countries. North African immigrants and their French descendants form the bulk of the French Muslim community. Abdelhamid Abaaoud, the alleged mastermind of the plot, was a Belgian of Moroccan origin whose father recently moved back to the North African kingdom. Moroccan intelligence reportedly assisted the French in tracking down Abaaoud and his accomplices. And three days after the attacks, Turkish police announced that they had detained eight ISIS-linked Moroccans who had traveled to Istanbul from Casablanca and planned to continue on to Germany. Meanwhile, Moroccan authorities regularly disrupt terrorist cells plotting attacks at home.

For its part, Tunisia is mourning the loss of two of its own who were among the victims in Paris. The small country has earned the unfortunate distinction of being the largest exporter of foreign fighters to Syria and Iraq over the past four years -- at least 3,000 so far. In recent days, Tunisian authorities have arrested seventeen Islamist militants for allegedly planning attacks against tourist and security locations in Sousse, the site of this summer's beach massacre of thirty-eight tourists by a self-proclaimed ISIS member. Like the Paris attackers, some of the Tunisian plotters arrested on November 16 had traveled to Syria for training.

In the longer term, the attacks could roil the deep security, political, and economic connections between these countries and France. If the EU begins deporting more radicals, many of them will likely end up in North Africa, exacerbating the threat of terrorism from al-Qaeda in the Islamic Maghreb and affiliated groups. Moreover, France remains the largest trading partner, largest source of foreign investment, and a key source of remittances for Morocco and Tunisia, so its economic and social health in the wake of the attacks will have a direct bearing on these states' trajectories. Tunisia has a particularly strong interest in seeing France thrive given its own struggles to complete a democratic transition, rebuild its economy, and fend off regional security threats. Accordingly, part of any U.S. assistance to France should be earmarked for bolstering common allies in North Africa, for whom ISIS is on the doorstep if not already inside the house.

— Sarah Feuer 

Why isn't Turkey curbing the flow of Syrian refugees and ISIS returnees into Europe?

Before the Paris attacks, Turkey was in talks with the EU to stem the flow of Syrian refugees. The attacks will raise the immediacy of that issue, with Turkey likely pledging to create a better refugee registration and hosting system. It may also agree to become a "readmission" country, allowing the EU to transfer Syrians who have entered the continent illegally to safe destinations in Turkey. In return, Brussels may yield (albeit gradually) to Ankara's longstanding demands for lifting visa restrictions on Turkish citizens traveling to Europe.

Post-Paris dynamics will also rally European support around Turkey's call for establishing a safe haven in northern Syria. For its part, Ankara will improve its cooperation with EU capitals to prevent the return of ISIS foreign fighters from Syria to Europe.

In the longer term, Ankara will leverage its newfound bargaining power with Brussels to jumpstart its EU accession talks. France has already signaled that it will lift its objections to unfreezing five of the thirty-five "chapters" in that process, and it will likely urge Cyprus to allow the unfreezing of another six. EU accession is one of the few remaining anchors of liberal democracy in Turkey, and rejuvenating the talks would strengthen that anchor.

Yet any such progress will depend on stemming the flow of foreign fighters to and from Syria. Several of the perpetrators of the Paris attacks had spent time in Syria after crossing over from Turkey, and many Europeans no doubt wonder about Ankara's actual commitment to addressing that issue. Moreover, the attacks will likely bolster far-right and xenophobic political parties in France and elsewhere that have made opposition to Turkish accession central to their platform. Last but not least, given the concern over Turkish jihadists in Syria, EU countries will think twice before granting Turks visa-free access.

— Soner Cagaptay

How can Washington bring its Arab allies back into the fight against ISIS?

As the New York Times reported before the Paris attacks, "The Arab allies who with great fanfare sent warplanes on the initial missions [in Syria] a year ago have largely vanished from the campaign." The reported reason was that Saudi Arabia and the United Arab Emirates have shifted their attention to Yemen, as has Jordan, which was additionally affected by the Islamic State's grisly execution of a captured pilot. By contrast, the rarely stated reason is that the GCC countries are conflicted by events in Syria.

Fearing Iranian troublemaking and regional ascendency in the wake of the nuclear deal, GCC leaders would prefer an outcome in Syria that delivers a strategic setback to Tehran -- in addition to displacing President Bashar al-Assad, whom they have loathed since he described them as "half-men" during the 2006 Israel-Hezbollah war. Hence the flow of Saudi and Qatari support for Syrian rebels, delivered with few of the scruples attached to U.S. and other Western military aid. Any fear of domestic jihadist blowback was apparently deemed a problem for tomorrow.

The challenge for Washington is to convince these monarchies that the United States has their back on Iran, acknowledging the threat that Tehran's hardliners pose rather than dismissing it as Arab paranoia. In return, it will seek Gulf support for a Syria outcome that does not bolster Russia or Tehran -- which could also help GCC leaders garner moderate Islamic legitimacy.

— Simon Henderson

Are many thousands of U.S. boots on the ground the only way to defeat ISIS?

Many of the proposed fixes to the campaign against ISIS involve "game-changing" moves such as committing large Western ground forces. This is just not going to happen, for a variety of reasons. As seen in past wars, however, incremental improvements in various aspects of the campaign could yield cumulative effects whose results could in turn be decisive.

For example, a combination of new tactics, operational concepts, and technologies enabled the Allied victory in the Battle of the Atlantic in 1943, Israel's defeat of Syrian air defenses in Lebanon in 1982, and the 2007 "surge" that turned the tide of the Iraq war. In the counter-ISIS campaign, such a shift would entail intensified air operations, less restrictive rules of engagement, and the embedding of U.S. advisors with local ground forces. More important, in accordance with Secretary of Defense Ashton Carter's recent promise, it would entail an intensified campaign of Special Forces, airmobile, and armored raids in eastern Syria by relatively small Western (e.g., French and American) units, aimed at wreaking havoc in the Islamic State's rear areas and keeping it off balance. These raids would be launched in concert with offensives by Syrian Kurdish and Arab forces (if they can overcome their traditional rivalries) along their line of contact with ISIS.

This new concept would threaten the group on two fronts in eastern Syria and place it on the horns of a dilemma: counter the mobile Western raiders running loose in its rear areas and disrupting its lines of communication, or fight the Kurdish and Arab forces breaking down its front door? ISIS units forced into the open to deal with either of these threats would be vulnerable to punishing coalition airstrikes.

The United States should also carry out a focused information campaign that leverages coalition military successes to create an image of restored momentum, thereby producing a bandwagon effect in which the Islamic State's enemies sense the group's vulnerability, commit to the fight, and pile on. An overstretched and beleaguered ISIS would thus face the threat of uprisings from within and attacks from without -- in Syria and perhaps even in Iraq.

This enfeeblement of ISIS should pave the way to establishing humanitarian safe havens and sustainable local political arrangements in Syria, as a first step toward dealing with the refugee problem and building up an effective moderate opposition. And, in an ironic reversal of the coalition's original campaign logic, success in Syria may eventually create military and diplomatic opportunities in Iraq.

— Michael Eisenstadt

Why has ISIS been able to establish and maintain control in eastern Syria?

Military factors aside, the prevailing social, demographic, and economic situation in the eastern part of the country made it ripe for an ISIS takeover. The group's chosen capital, Raqqa, is no prize in of itself -- it does not have a prestigious past, nor is it of major strategic importance. It is simply the worst of Syria's provincial capitals in terms of human development.

Raqqa currently has around 300,000 inhabitants (including 80,000 refugees), compared to 15,000 in 1960. Two-thirds of the population lives in large, informal suburbs. These are rural people who were driven toward the city by poverty and rapid population growth in the countryside. Raqqa province has the highest fertility rate in Syria: eight children per woman. It is also the most rural and agricultural province, with a majority of the workforce in the farming and mining sectors. Its average education level is the lowest in the country; one-third of women are illiterate, and early marriages are still the norm.

In addition, Raqqa was already living under some of the rules of sharia even before the 2013 ISIS invasion. When I visited the city in previous years, I did not encounter a single restaurant that served alcohol, in contrast to other Syrian cities. In this purely Sunni community (less than 1% Christian before 2013), ISIS is like a fish in water.

Economically, the plots of land that locals received during various reforms in the 1960s are no longer sufficient to feed families whose numbers have quintupled in half a century. Competition for land and water leads to conflicts between tribes that ISIS knows very well, and the group has used the situation to consolidate power. These land issues motivated the offensive against Kobane, where ISIS hoped to expel the Kurds and distribute their properties to its tribal supporters.

— Fabrice Balanche

Does ISIS threaten Israel?

At present, the ISIS branches that are active on Israel's borders do not pose a major threat to it, nor do radicalized individuals inspired by the organization. The border threat is focused to the south and north; ISIS does not have any notable presence in the West Bank.

The ISIS branch in the Sinai Peninsula has proven to be relatively strong compared to other branches, but Israel is more than capable of coping with it given the strengthened fence on this frontier, as well as the advanced intelligence and combat capabilities that monitor this area constantly. Israel is also coordinating with Egypt to reduce the possibility of surprises.

To the north, ISIS affiliates have very limited presence close to the Syrian border, and their offensive capabilities in the Golan Heights are not significant at the moment. Thinking in advance about this potential threat, Israel has fortified the fences there and strengthened its military presence with additional forces and intelligence capabilities.

As for the threat posed by radicalized individuals, despite some high-profile cases, only about forty-five Israeli Arabs have left the country to join ISIS, which is a low number. Furthermore, authorities have reliable information about their identities, so if they try to return home, they will be apprehended the minute they arrive. Israel's border control measures are some of the most restrictive in the Western world, so it has very good information about who arrives and who leaves. Notably, the Palestinian Authority and various Israeli Arab communities are also trying to deal with the threat of radicalization themselves -- a welcome force multiplier to the Israeli government's efforts.

The major threat that Israeli officials do fear regarding ISIS is the possibility of the group getting its hands on unconventional weapons such as a "dirty bomb" or chemical weapons. But they admit that the probability of this scenario is low at present.

For now, Israel has much more potent threats to its security than ISIS -- namely the radical Iran-Hezbollah axis. This axis has significantly more offensive capabilities and resources to threaten Israel, whether by targeting its citizens abroad or targeting population centers inside Israel during an armed conflict.

— Muni Katz and Nadav Pollak

How should Washington respond to its allies' need for leadership?

The Paris attacks reminded Londoners of their own city's vulnerability, and the threat posed by jihadist fighters returning home from Iraq and Syria to live in a society they probably despise -- and Albion's current deficit of fighting spirit. Lacking an aircraft carrier of its own, Britain announced on November 18 that it was sending the destroyer HMS Defender to support the French aircraft carrier Charles de Gaulle in its mission to tackle ISIS forces.

The Defense Ministry statement accompanying this move could have been a script from the old television sitcom Yes, Minister, which used to poke fun at the British art of political decisionmaking -- namely, its preference for elegantly finessing difficult choices. The official news release did not point out that the French aircraft would likely be hitting targets in Syria. Nor did it mention that Britain's own anti-ISIS strikes are currently limited to Iraq because Prime Minister David Cameron is fearful that he cannot get parliamentary approval for expanding operations to Syria. To complete the appearance of farce, the HMS Defender's specialist role is air defense -- a threat that ISIS does not pose to the French carrier group.

Opposition to more extensive deployment against ISIS comes from all corners of the British political spectrum -- rebels in Cameron's own Conservative Party, the newly significant Scottish Nationalist Party, and also the main Labour opposition party, now led by longtime left-wing maverick Jeremy Corbyn. These disparate factions are united by their reluctance to be involved in what some consider "other people's wars," a mindset that tends to underplay the jihadist threat at home.

The British navy's usual partner is the U.S. Navy. Defender's sister ship, HMS Daring, was a constant companion to the carrier USS Abraham Lincoln during its Persian Gulf deployment three years ago, when Iranian air and naval units were real threats to operations.

In times of crisis, U.S. allies look to Washington for leadership in policymaking. For the moment they see little of that, despite White House briefings to the contrary. The immediate consequence will likely be continued fence sitting. When there is frantic signaling, as now from London, Washington needs to respond, and publicly.

— Simon Henderson

How can a highly adaptive and ruthless enemy like ISIS be stopped?

The Islamic State can be likened to a dangerous pest or invasive species. From that perspective, the minimum objective should be to reduce the group to the point where life can go on normally, while maintaining vigilance against any reemergence and, when necessary, taking appropriate prophylactic measures.

ISIS has propagated in an environment of instability and fanaticism, brought about by the collapse of state and society and exacerbated by ineffectual responses. The pest has grown strong, increasing its numbers and geographic range. It has become invasive, jumping borders and spreading well beyond its original territory. To effectively control it, the organism itself must be directly attacked, primarily with military force, and the environment in which it has flourished must be altered.

Directly attacking the pest entails:

• Reducing its territory through offensive military operations to limit its resource base and the areas it can directly affect.
• Killing its foot soldiers through attrition operations to reduce its capabilities and scope of action.
• Killing the "queens and consorts" (the Islamic State's leadership) to disrupt its ability to create new followers and direct their activities.
• Increasing the number of predators and competitors on the landscape who can attack it directly and draw resources away from it (i.e., more Kurdish and other minority fighters, and more moderate rebel units).
• Killing its colonies (Libya, Sinai, cells in Europe) before they become too strong.

Changing the environment is broader and goes beyond military measures. It includes:

• Denying sustenance (recruits, money, arms) to the organism by sealing its borders, closing off revenue sources (e.g., petroleum sales), and countering its ideology.
• Reducing its attractive qualities by reducing elements in the environment (i.e., the Assad regime) that make it look attractive.
• Demonstrating that life under ISIS is likely to be brutal and short for its supporters (i.e., killing them, preventing governance, reducing quality of life in ruled areas).

Because ISIS is a highly adaptive and ruthless species now in possession of significant resources, these measures need to be applied simultaneously and persistently. Even if they are largely successful, continuous surveillance and reapplication of treatment will be required. Just like for those yellow jackets that come back to your yard every year, or the kudzu that clogs your stream.

— Jeffrey White

What impact will the Paris attacks have on other Sunni and jihadist groups?

While it is still too early to tell, there are strong indicators that the attacks could further isolate ISIS from other violent and nonviolent Sunni groups in the region. Nonviolent Sunnis issued condemnations of the attacks the very next day, calling them acts of terrorism with no basis in Islam. And while the scale and attention of the operation might encourage other jihadist groups to follow suit, they probably cannot muster the resources to do so. This includes al-Qaeda, which has a comparatively weak central command and is currently focused on competing with ISIS and Shiite groups in Syria and Yemen.

Setting aside the human tragedy that ISIS is still causing, the above implications might further support the argument that the recent attacks are symptoms of a group in retreat rather than on the ascent. Moreover, unlike al-Qaeda's 9/11 attacks, the Paris operation may have been poorly timed -- ISIS already faces mounting rhetorical and physical pressures from local Arab governments such as Egypt, creating disincentives for potential Arab recruits to join.

Even so, given the Islamic State's unique appeal to certain foreign communities and its structural and financial independence from al-Qaeda and Gulf backers, the group will likely remain eager to plan attacks abroad, despite -- or perhaps because of -- its marginalization of other Sunni actors. The task before the international community is to establish greater security and intelligence coordination on ISIS recruitment overseas in addition to countering the group on the battlefield.

(Note: All statements of fact, opinion, or analysis expressed above are those of the author and do not reflect the official positions or views of the U.S. government.)

— Jacob Olidort

How does ISIS finance itself?

The Islamic State is primarily financed through criminal activities in the parts of Syria and Iraq it controls. Its members steal livestock, sell foreign fighter passports, tax minorities, run a sophisticated extortion racket, kidnap civilians for ransom, loot antiquities, and much more. The group also makes about $40 million a month from illicit oil sales alone. But these sources primarily support expensive state-building and war-fighting enterprises back home, ranging from paying teacher salaries and collecting the garbage to bribing tribal leaders and rewarding its fighters.

As for its supporters abroad, ISIS has encouraged foreign cells to finance their operations through local criminal activities or legal sources such as welfare benefits and bank loans. Abusing charities is another funding stream available to terrorist operatives in the West. Thus far, the various financing schemes uncovered by European authorities have focused on raising funds for terrorist activities in Syria and Iraq, but small amounts could easily be skimmed off the top for operations inside the continent and elsewhere.

Unlike previous attacks in France, which were almost all lone-offender plots inspired by ISIS propaganda, the Paris attacks were planned outside the country. In the event that ISIS leaders wanted to send funds to finance this operation, they could have given small sums of money to various foreign fighters returning home to Europe, enough to carry on their person. The group has also engaged in backdoor banking, using institutions just outside its areas of control to access the international financial system. Yet while the group's governance and military expenses in Syria and Iraq are high, carrying out an attack in the West is fairly cheap.

— Matthew Levitt

Why didn't France call NATO for assistance?

Article 5 of the North Atlantic Treaty lays out the principle that an attack against one ally "shall be considered an attack against them all." In the wake of the 9/11 attacks, the United States invoked this article for the first time in NATO's history. Yet after the Paris attacks, France chose not to, even while intensifying its airstrikes against ISIS in Syria in cooperation with Washington.

Instead, in a solemn address to parliament on November 16, President Francois Hollande called on the UN Security Council to "to adopt a resolution expressing our common will to combat terrorism." This move is consistent with his call for the formation of a "large, single coalition" against ISIS, including Russia. It also reflects the extent of a threat that reaches far beyond NATO, as demonstrated by attacks in Tunis, Beirut, and the Sinai.

President Hollande also invoked Article 42(7) of the Treaty on European Union, which states that "if a Member State is the victim of armed aggression on its territory, the other Member States shall have towards it an obligation of aid and assistance by all the means in their power." In a deeply integrated bloc like the EU, France's homeland security is intertwined with that of its neighbors. Although authorities in Belgium and Germany have already made arrests in connection with the attacks, the larger message is that France -- for years at the forefront of the continent's defense efforts from Mali to Syria -- can no longer bear the costs or risks alone. The unanimous support that EU defense ministers have expressed in response is good news for Europe and NATO -- if the Europeans deliver.

— Olivier Decottignies

How could the U.S. military effort against ISIS be made more effective?

ISIS has mastered the counter-stroke whenever America's Iraqi and Syrian allies have landed a painful blow on the group with coalition help. Yet while high-visibility terrorist actions off the battlefield are a potent distraction, the coalition's successes on the battlefield should not be overlooked, since they represent the most tangible and realistic means of striking back at ISIS. The terrorist movement values attacks abroad because they provide a countervailing narrative to its gradual military collapse in Iraq and Syria. So the first response to the Paris tragedy is to stay on track with the grinding coalition campaign against the ISIS-held cities of Ramadi, Raqqa, and Mosul.

Second, the U.S.-led coalition should boost the visibility of its military efforts, doing a better job of seizing media attention back from ISIS, holding it, and preparing for the group's next distraction. For example, the buildup to the successful Sinjar offensive in Iraq was significant, as was the subsequent media coverage. NATO spin doctors first learned to feed the media's insatiable appetite for dramatic imagery and detailed briefings during the 1999 Kosovo war, in part to deny this key terrain to the Milosevic regime. Today, the coalition needs to up its game in information operations, delegating more IO authority to lower levels at the headquarters controlling the fight in Iraq and Syria. Preparing IO options in advance for high-visibility strikes on ISIS leaders and key units would also help. The recent aerial destruction of ISIS oil tankers and the drone strike on "Jihadi John" are just the kinds of actions the coalition needs to have on tap. Some spectacular news should be kept quiet until the coalition needs a boost, which requires great discipline. And some strikes should be made more spectacular than strictly necessary (e.g., via more pyrotechnics and bigger devices) to show Arab publics what they can expect when the world's greatest military powers are on their side.

Alongside showmanship, the coalition needs to fight harder. Without getting into sensitive details, the United States should significantly loosen the current rules of engagement (ROE), allowing lower-level commanders to approve strikes within a more reasonable timeframe if the risk of civilian deaths is small. This is the equivalent of downgrading platinum-standard target vetting to gold-standard. It would bring operations back into the realm of normal Western air campaigns and revolutionize the coalition's ability to gut the enemy. Any such shift should be put into effect before it is announced. The first few weeks of an enhanced air campaign would be remarkably painful for ISIS, forcing its cadres to adapt in ways that help them survive but make them less effective.

If the U.S. government cannot move its own goalposts on target vetting, then it should create a "Coalition of the More Willing" that is not bound by U.S. ROE. American military units could cope quite well with an allied force that has more leeway to strike than they do -- there should be no hesitation about providing France with any ISIS leadership coordinates that the United States has been agonizing over whether to strike.

— Michael Knights

How much can the Kurds do against ISIS?

The Kurds are limited in manpower and reach, are considered provocative by others needed for this fight (especially in Baghdad and Ankara), and are neither fully united nor fully democratic. But they are the best there is: disciplined, effective, friendly, and totally committed to the battle against ISIS. Kurdish militias -- the Peshmerga in Iraq and the People's Defense Units (YPG) in Syria -- have demonstrated their military worth not only by successfully defending the Kurdistan region of Iraq against repeated ISIS assaults, but also by liberating significant areas such as Sinjar and Kobane.

So in order to fight ISIS faster, the United States should do even more to aid its Kurdish allies. In addition to the current airstrikes, arms supplies, and intelligence and Special Operations support, Washington could deliver more weapons directly to frontline units, accelerate joint planning for new military campaigns, and enhance coordination about "the day after" ISIS is pushed out of areas. Equally important, Washington should step up its humanitarian, development, and reconstruction assistance. The Kurds are suffering acutely under multiple economic burdens: a cutoff of funding from Baghdad, drastically lower prices for their own greatly increased oil production, hundreds of thousands of refugees, and the huge costs and devastation of war.

As for Turkish and Arab concerns, the Kurds' own limitations are the best insurance policy -- they are simply too few in number to take over much more of Syria or Iraq. The Kurds in Iraq have also largely kept their promise not to engage in ethnic cleansing as they advance. And the Kurds in Syria have kept their promise not to attack Turkey or aid their PKK sister organization in its doomed fight against the Turkish government.

— David Pollock

Why is Turkey staying out of the anti-ISIS fight, and how can Washington persuade it to be more helpful?

Turkey is a reluctant warrior against ISIS for at least three reasons. First, while it sees the group as a threat, it is more concerned with two other priorities: countering Kurdish nationalism of the sort advocated by the Kurdistan Workers Party (PKK) and its Syrian sister organization the Democratic Union Party (PYD), and ousting Bashar al-Assad's regime. Second, while Ankara does not directly support ISIS, it has turned a blind eye to some of its activities, including in Turkey, and it allows freedom of movement to individuals transiting its territory to fight Assad regardless of which group they might belong to. Third, Ankara is attempting to use the prospect of more forceful action against ISIS (beyond opening bases to U.S. operations and conducting a few desultory airstrikes) as leverage to gain Washington's acquiescence on the Turkish no-fly-zone idea in northern Syria, and to pressure the PYD to be more aggressive against Assad and less expansionist in Arab areas near the border with Turkey.

There is no pressure that can change President Recep Tayyip Erdogan's position on this issue. If the United States and its allies want a more active Turkey, then they must at least partially accommodate Ankara. That means taking more care in empowering the PYD and adopting a tougher position on Assad, most likely to include a no-fly zone. Ironically, Washington is reliant on the PYD not only because it refuses to commit U.S. ground troops, but also because it has not been able to enlist serious Turkish participation in the fight. The more Turkey can be persuaded to oppose ISIS actively, the less the United States will need to rely on the PYD. The opposite is also true, however -- the more Washington embraces the Syrian Kurds, the more reluctant Turkey will be to enable such an alliance.

— James F. Jeffrey

Does ISIS truly want to create an Islamic State, and would it leave the West alone if the West left it alone?

Unlike previous ISIS-inspired plots, the Paris attacks were "prepared and planned elsewhere, with outside involvement." That alone is a significant tactical shift for ISIS, and one that cannot be explained away as a response to gains made by the U.S.-led coalition in Syria and Iraq -- such attacks take much longer to prepare, and they were surely already in the works when ISIS suffered its most recent setbacks. Moreover, the attacks did not take place in a vacuum -- they followed a series of other international terrorist strikes claimed by ISIS in Turkey, Lebanon, and Egypt.

Yet while the recent foreign plots were a new step for the group, they should not have been unexpected. ISIS describes its goals as "enduring and expanding," but that is not all it seeks to accomplish. Its ideology is explicitly apocalyptic, looking to draw "the Romans" (i.e. the infidel West) into a dramatic battle that will presage Judgement Day. Prophecies about an end-of-days battle in the Syrian town of Dabiq permeate ISIS statements and literature. The group's English-language magazine is even called Dabiq; as its editors explain, "The area will play a historical role in the battles leading up to the conquests of Constantinople, then Rome." The prophecies to which ISIS adheres demand conquest not just in the Middle East, but all over the world. As Will McCants explains in his excellent book The ISIS Apocalypse, "The Islamic State has stoked the apocalyptic fire," fanning the flames of a dangerous ideology that respects no boundaries.

— Matthew Levitt

What happens if Europe turns up the heat on Syrian refugees?

Since the Paris attacks, several countries have decided to suspend the reception of Syrian refugees or allow entry to Christians alone, who are unlikely to be creatures of ISIS. This measure is partly an excuse to avoid taking their share of responsibility for the Syrian drama. If the decision stands and becomes a universal policy in Europe, it would engender feelings of hopelessness among many refugees that could in turn spur a huge wave of radicalization, particularly among those who fought the Assad regime.

In my many interviews with Syrian refugees in Lebanon, Turkey, and Jordan over the past two years, I noticed their strong bitterness against Western countries: "You have pushed us to lift against Bashar al-Assad, you have promised us military help, but nothing came, as when Assad crossed the redline. Because we have trusted, we lost everything: we cannot come back to Syria, we are stuck in this miserable camp in Lebanon where we have no future."

Indeed, humanitarian aid is falling, and Lebanese authorities are exerting stronger pressure on refugees to return to Syria. Heading for Europe is often their only hope, even if the quest takes years. The complete closure of European borders would strike many Syrian refugees as a new betrayal by the West. "You have betrayed us, and only ISIS can help us regain our dignity": that is how most of my interviews ended in 2014, and one year later the situation is worse for the refugees.

— Fabrice Balanche

How useful is Russia in combating ISIS?

Numerous reports indicate that the vast majority of Russia's airstrikes have not been directed against ISIS targets. Rather, Moscow's Syria intervention has exacerbated the flow of refugees fleeing Assad, emboldened ISIS by helping to eliminate its opponents (including those backed by the West), and disheartened U.S. regional allies in the absence of a coherent Western response.

Vladimir Putin's consistent support for Assad since 2011 also contributed to the growth of ISIS. According to an extensive July report by Elena Milashina of Novaya Gazeta, one of the few remaining independent newspapers in Russia, the Kremlin's special services have controlled the flow of Islamist radicals from Russia into Syria since 2011, and sometimes even assisted their entry. Other reports and private conversations with experts support this report. Rather than help solve the problem, Russia's Federal Security Service preferred to hand it off to others. As a result, terrorist attacks in Russia and elsewhere will likely increase once these fighters return home. Meanwhile, Russia's policies in the North Caucasus have done little to reduce the pool of potential recruits for ISIS and other terrorist groups. In the past, Putin has not shied away from supporting Islamists abroad. For instance, he did not object when Assad allowed radical Islamists to transit Syria into Iraq.

It is in Russia's interest to genuinely fight ISIS, especially given the instability in the North Caucasus, but Putin's primary concern is to stay in power and divide the West. He is using the tragic Paris events as an opportunity to push the West to accept his agenda. A true global leader considers international security rather than pushing his own narrow interests at the expense of others, including his own people. In this context, Putin's Russia is a poor ally in the fight against ISIS.

— Anna Borshchevskaya