Friday’s attack on Paris, claimed by ISIS, was different. It was different in the scale of the carnage—the worst terrorist attack in Europe since the Madrid bombings, claimed by al-Qaeda, in 2004; the worst violence on French soil since World War II. Mass-casualty terrorist attacks are rare in the West, but this one has claimed at least 129 lives so far.

It was different in the methods used by the group. On Friday night, when it was still unclear who could have done this, the evidence of coordination and preparation seemed initially to point towards al-Qaeda, ISIS’s former ally and current rival, better-known for links to complex attacks on international targets, like the Madrid and London bombings. The attack on London a decade ago was the last time a mass-casualty suicide attack, involving multiple bombers, struck Western Europe. (The suicide bombing in Burgas, Bulgaria, in 2012, killed six people in addition to the single bomber.)

But it was also different from an al-Qaeda attack, because of the targets. As Rukmini Callimachi wrote for The New York Times:

The style of the attack was in line with the Islamic State’s tactic of indiscriminate killings and goes against Al Qaeda’s guidelines. In a 2013 directive, the leader of Al Qaeda, Ayman al-Zawahri, stated that Qaeda operatives should avoid attacks that could inadvertently cause the death of Muslim civilians and noncombatant women or children. … He argued that targeting markets, for example, was unadvisable because innocent Muslims might accidentally be killed. Although Qaeda branches have deviated from these guidelines on numerous occasions, their attacks reflect more carefully defined targeting. That was the case in the killings at the Charlie Hebdo office in Paris in January, when cartoonists were singled out and defined as legitimate targets because of what the group considered to be blasphemy against the Prophet Muhammad.

It was different in its reach. ISIS has never before conducted an operation on such a scale in Europe, though the past month has apparently shown the organization projecting violence further and wider than it has ever done. Since mid-October alone, the group and its local affiliates are believed to have conducted, or at least inspired, three or four historic attacks, though attribution is murky in some cases.