Since emerging as a powerful force two years ago, the Islamic State had focused its energies on building its self-proclaimed caliphate in the Middle East. The carnage in Paris, for which the group has claimed responsibility, demonstrated it can unleash a ferocious, coordinated assault far from its home turf.
"It is clear that the threat from ISIL is evolving," British Prime Minister David Cameron said, using one of the acronyms for the group. "Last night's attack suggests a new degree of planning and coordination and a greater ambition for mass casualty attacks."
As French authorities worked to piece together the details Saturday, here are five ways to think about the terror attacks that claimed more than 120 lives in Paris.
1. Beyond The Middle East: Until very recently, ISIS fought and carried out attacks almost exclusively in Syria and Iraq. But the group has now claimed responsibility or been blamed for major terror attacks in four additional countries in the past month.
Turkey has blamed ISIS for a suicide bombing that killed more than 100 people at an Oct. 10 rally in Ankara, the worst terror attack in the country's modern history. ISIS, however, has not claimed responsibility.
ISIS has claimed responsibility for the Russian jet that was likely destroyed by a bomb after taking off from the Egyptian resort of Sharm el-Sheik, according to U.S. officials. This followed the recent launch of the Russian bombing campaign in Syria, though relatively few strikes have been directed against ISIS.
And in Lebanon, ISIS claimed responsibility for suicide bombings Thursday in southern Beirut, an area where Hezbollah is dominant. Hezbollah has been a major player in Syria, where it is fighting in support of President Bashar Assad.
And now comes the bloodshed in France, which has been carrying out a limited number of airstrikes against ISIS in Syria.
ISIS has been calling for supporters to attack the group's opponents worldwide, but until recently that hadn't happened on a mass scale. If ISIS is indeed responsible for major attacks in four separate countries, it demonstrates a vast expansion of its deadly reach.
2. Multiple Soft Targets: The unifying thread in Paris was that all were soft targets and did not appear to hold special significance for the terrorists.
By comparison, al-Qaida often favored major symbols such as the World Trade Center and the Pentagon in the Sept. 11 attacks, and U.S. embassies in Africa in a pair of 1998 bombings.
In Paris, at least six separate sites were hit at roughly the same time. It displayed a frightening level of coordination and seemed to guarantee heavy casualties. Even if one or two attacks had been thwarted, others likely would have proved deadly.
3. Europe's Vulnerability: The Paris attacks point to weaknesses France and other European countries face in combating terrorism.
France is among many countries with large, disgruntled Muslim populations. Some young Muslims are being radicalized at home, while others have headed to the Middle East to fight with ISIS, raising alarms among Western security services who fear they will return home to attack.
France has an estimated 5 million Muslims, or roughly 8 percent of the population. That's a huge community for authorities to monitor.
U.S. congressman Ed Royce, a California Republican, told CNN that 185 French Muslims have returned home after going to fight in the Middle East. That's not a particularly large number, but it appears a very small group — perhaps no more than eight — carried out the Paris attacks.
Entry into Europe and movement across national boundaries is relatively easy, as demonstrated by the migrant crisis on the continent this year.
There's no indication that the migrant influx has led to terror attacks. But the huge flow has shown that there's no real obstacle to moving across borders. Weapons are far less available in Europe than in the United States, but the Paris attackers reportedly had automatic rifles, grenades and suicide vests.
4. U.S. Has Mostly Been Spared: It's a remarkable fact, but since the Sept. 11 attacks in the United States, Muslim extremists have killed 26 people in just seven deadly attacks on American soil.
Security has been ramped up dramatically. Would-be attackers have often proved incompetent. Simple good luck has played a role.
Muslims in the U.S., both those born in America and those who have immigrated, tend to be more successful, better integrated, and have turned to radicalism less often than Muslims in Europe and elsewhere.
Terrorism worldwide has been surging since the Sept. 11 attacks, with more than 30,000 deaths last year, according to the U.S. State Department. Yet the U.S. has been largely unscathed at home.
5. Racking Up Powerful Enemies: The Islamic State has rapidly accumulated sworn enemies far beyond the borders of Iraq and Syria, and the combined forces lining up against ISIS will put increasing pressure on the group.
The U.S. began bombing the Islamic State last year in a coalition that includes several Arab countries as well. France and Russia are now bombing in Syria.
Iran, a Shiite Muslim nation, has also been actively fighting ISIS, a Sunni Muslim group. Iranian military leaders have been directing militias in Iraq and Iran strongly supports the Syrian government.
Egypt, meanwhile, has suffered a major blow to its tourism industry following the downing of the Russian plane. Lebanon's Hezbollah may escalate its role in Syria following the bombings of its strongholds in Beirut.
The Islamic State has not suffered any major setbacks since its dramatic rise, and its many opponents have not acted in a coordinated manner. But the group's manpower and weaponry pale when compared to the combined force of the enemies it now faces.
Greg Myre is the international editor of NPR.org. Follow him @gregmyre1.