The Islamic State's claim of responsibility for a trio of major attacks, including the assault on Paris, has led to a rapid reassessment of the extremist group and its aspirations.
Until a couple of weeks ago, ISIS appeared focused on building its self-declared caliphate, or Islamic empire, in its core areas of Syria and Iraq. But it now says it was behind attacks in France, Egypt and Lebanon that killed nearly 400 people in a two-week span.
Basic questions — like the group's goals or whether it's getting stronger or weaker — are being examined anew.
"We have only recently grown accustomed to thinking of the Islamic State as an actual state, much less a state sponsor of terrorism," writes William McCants, author of The ISIS Apocalypse. "It has been called a 'proto-state' and a 'quasi-state.' Whatever the terminology, it's much more than an insurgent group now — and it has millions of dollars at its disposal to fund its military adventures at home and abroad."
ISIS has become many different things to different people. And since its leaders operate in the shadows, trying to make sense of the group can be like the proverbial group of blind men describing an elephant.
Experts on Islam focus on the group's Islamic postings. Terrorism analysts points to its organizational skills and reach in recent attacks. Oil experts stress the financial resources the group has accumulated from oil sales. Middle East analysts point out how ISIS has exploited local political grievances.
Let's sort through some of the issues surrounding ISIS in the wake of the Paris attacks.
What Does ISIS Want? Until very recently, ISIS appeared to have a clear focus on building its caliphate at home. ISIS' leaders openly rejected the al-Qaida model of attacking the West on the grounds that could galvanize those countries to attack the group in the Middle East.
But in the wake of the recent ISIS attacks in Paris and elsewhere, the group appears to be taking a fundamentally different approach.
"The international community could take some small comfort from the Islamic State's domestic focus — better it spend its money on infrastructure than on financing terrorist plots abroad," writes McCants.
"But if the Islamic State has now added foreign operations to its government spending, as the recent attacks suggest, the prospects are frightening," he adds. "It has the wealth of a state, the ambition of an imperial power and an enemies list that reads like the roll call of the United Nations."
What's Life Like In The Caliphate? It has been impossible to gain a clear picture of life in ISIS territory since the group consolidated its hold on large parts of Syria and Iraq last year. Occasional fragments point to harsh rule with ISIS imposing its extreme version of Islam on all under its rule.
The Daily Beast has been running a series this week based on conversations with an ISIS defector who says the group has been facing mounting problems, including a sharp drop in foreign recruits, who previously flowed in.
Foreign fighters have often been sent directly to the front lines and have been killed or wounded by the thousands, said the defector, identified as Abu Khaled.
The author of the series, Michael Weiss, writes:
"This sudden shortfall has led to a careful rethinking by ISIS high command of how inhabitants outside of Syria and Iraq can best serve the cause. 'The most important thing,' Abu Khaled said, 'is that they are trying to make sleeper cells all over the world.' The ISIS leadership has 'asked people to stay in their countries and fight there, kill citizens, blow up buildings, whatever they can do. You don't have to come.'"
Is ISIS Getting Stronger Or Weaker? Some analysts have long warned that ISIS was likely to carry out spectacular attacks abroad, and that President Obama and other leaders have consistently underestimated the group.
And attacks outside its core area are not new for ISIS. The group has been linked to nearly 100 actual or planned attacks outside of Syria and Iraq since the fall of 2014.
But most appeared to be of the "lone wolf" variety and were not on the scale the group has claimed since Oct. 31: the downing of a Russian plane (224 dead), a pair of suicide bombings in Beirut, Lebanon (44 dead), and the Paris attacks (129 dead).
Some see these actions as the work of a group that's on the defensive and is feeling squeezed.
"The Paris assault appears to be the Islamic State's response to its recent territorial losses and the slowly growing coalition against it, which includes France. Its leaders are trying to show anti-Islamic State countries that there is a price for trying to take it down," writes Harvard professor Stephen Walt in Foreign Policy.
He argues that Western countries have a habit of overreacting to such attacks, which can play into the hands of groups like ISIS.
"If the Islamic State can get France and other countries to crack down on their Muslim citizens and also get the West to reoccupy large swaths of the Middle East, then its false narrative about the West's deep and intrinsic antipathy to Islam will gain more credence," Walt adds.
ISIS Supporters Abroad: Extremists have declared loyalty to ISIS in several Muslim countries, including Afghanistan, Pakistan, Egypt, Saudi Arabia and Libya. The group's successes have given it broad appeal among radicals across the Muslim world and beyond, making ISIS even more dangerous.
It's extremely difficult to tell whether this constitutes a genuine web of connections that can be controlled by ISIS central in Syria, or whether it's just local radicals looking to raise their own profile in their home countries.
Either way, the far-flung ISIS supporters pose a threat. One of the key unanswered questions in the recent spate of attacks is whether they were directed by ISIS leaders or carried out independently. The sophistication and organization suggest the attacks were carefully orchestrated, but investigators are still putting the pieces together.
The Anti-ISIS Coalition Is Growing: ISIS has succeeded in uniting world powers to fight against it, at least from the air. The countries that have carried out airstrikes against the Islamic State since last year include the U.S., Russia, France, Britain, Canada and Australia, as well as several Arab states.
So far, no foreign power has been willing to send in a large ground force that could dislodge ISIS.
The group has lost more territory than it has gained in the past year, yet still has a firm grip on eastern Syria and many parts of western and northern Iraq.
ISIS lacks friends, allies or sympathetic countries that can provide substantial assistance or weapons. The group has sustained itself financially and put well-armed fighters on the battlefield, but all these resources will need to be replenished.
The biggest potential limiting factor for ISIS may be opposition from other Muslims.
The group's Muslim opponents include Kurds fighting in northern Iraq and Syria, Sunni Arabs who have been displaced by ISIS takeovers, Syrian rebel groups backed by Saudi Arabia and Turkey and Shiite militias in Iraq.
Mainstream Muslim clerics have tried to undermine ISIS' claims to religious authority. In Brussels, Muslims have already taken to the street to protest the ISIS attacks in France.