Sometime during the attack on the Pulse nightclub in Orlando, Florida, shooter Omar Mateen reportedly called 911 and pledged his allegiance to ISIS and its leader, Abu Bakr al-Baghdadi, according to authorities.
While it is possible that evidence will emerge showing that ISIS directly ordered or facilitated the attack on the popular gay nightclub, so far it has not. ISIS has claimed responsibility for the attack, stating that it was carried out by "one of the soldiers of the Caliphate in America." But the group offered no evidence it was in any way involved in the attack, and President Obama said this morning after meeting with the FBI that "[a]t this stage, we see no clear evidence that [Mateen] was directed externally."
To the victims and their families, of course, it makes little difference whether a terror attack was directed and facilitated by a powerful organization with lots of resources or just committed by a random individual or small group.
But in the bigger picture of US efforts to prevent attacks and counter threats, the distinction between plots that ISIS directs and ones it merely inspires is hugely important. They're different kinds of threats that have different risk factors and require different solutions.
Any plots directly organized and conducted by ISIS are, by nature, likely to be larger, more sophisticated, and deadlier — but they will also be much easier to disrupt. Lone wolf plots inspired by ISIS or al-Qaeda, on the other hand, are generally less deadly — but also, by their homegrown and often haphazard nature, much harder to spot and disrupt.
What the FBI has determined thus far about the Orlando shooting
The FBI had previously investigated Mateen several times, including in 2014 when it learned of his connection to Moner Mohammad Abusalha, who had traveled to join the Nusra Front, ISIS’s al-Qaeda-affiliated rival in Syria, and became the first American suicide bomber in Syria. However, each time the FBI ended up clearing Mateen.
"This seems like a typical case of an ISIS-inspired attack," Amarnath Amarasingam, a fellow at George Washington University's Program on Extremism, told me. "And based on the way in which the Islamic State took credit for the attack, they waited a while to see if the supposed 'pledge’ is real."
In other words, it appears that Omar Mateen may have, like the San Bernardino shooters, been a so-called "lone wolf" who was inspired — but not directed — by ISIS. The group may have merely found out about Mateen’s pledge of allegiance the same way the rest of the world did and responded accordingly.
The opposite was true in the November 2015 terrorist attacks in Paris that killed 130 people: ISIS’s external operations wing is believed to have directly ordered and facilitated those attacks.
The attacks in Orlando and Paris were both horrific, senseless tragedies that killed innocent people. So why does it matter whether they were directed by ISIS? It's a critically important distinction — and one that almost never gets addressed.
Homegrown attacks: often amateurish but harder to catch
In the context of jihadist terrorism, a "homegrown" terrorist attack is one carried out by people who have, on their own, adopted the extremist ideology espoused by ISIS or al-Qaeda and decided to carry out an attack independently, without receiving any direct orders, training, financing, or other support from the central leadership of ISIS or al-Qaeda.
Maybe they read a few issues of ISIS's online propaganda magazine, Dabiq, or watched a few YouTube videos of extremist sermons, such as those by the now-deceased radical Yemeni-American cleric Anwar al-Awlaki, and became convinced that it was their duty to attack America.
They buy a gun or build a bomb using directions they find online, pick a target they think they can attack pretty easily and that maybe is vaguely symbolic, and launch their attack. They might make a "martyr" video, pledge allegiance to al-Qaeda or ISIS, or perhaps just post some sort of manifesto online indicating their intentions. Or they may do none of that and just shout al-Qaeda or ISIS slogans during the attack.
Because the perpetrators of these kinds of attacks have not received any kind of training or direction from al-Qaeda or ISIS, their attacks are often amateurish, targeting places that are not very secure or well-defended, and are on a much smaller scale.
The 2013 Boston Marathon bombing is a good example of this kind of attack. The two bombers, Dzhokhar and Tamerlan Tsarnaev, detonated pressure cooker bombs they made themselves using instructions from Inspire magazine, the English-language digital magazine produced by al-Qaeda in the Arabian Peninsula, near the finish line of the Boston Marathon, killing three people and injuring more than 260 others.
Authorities concluded that the Tsarnaev brothers "were 'self-radicalized,' having developed a personal militant ideology that drew from disparate sources without being directly connected to any of them."
Although the Boston Marathon bombing — and the subsequent manhunt for the attackers that shut down the city of Boston — was a dramatic attack that received major media attention, the number of fatalities was thankfully very low (though many more were injured).
If the two attackers had received formal training in bomb-making from a group such as al-Qaeda or had access to more advanced weaponry, the body count could have been much, much higher. But that would have also made the attacks easier for law enforcement to trace and stop.
That’s because it would have required the Tsarnaevs to communicate with heavily monitored jihadist groups and perhaps travel abroad for training, all of which might have set off law enforcement red flags. That is the nature of such homegrown attacks — the things that make them relatively less deadly also make them more likely to succeed.
The Orlando attack, which left at least 49 victims dead and more than 50 injured, is the deadliest mass shooting in US history, and the death toll is much higher than other so-called "homegrown" attacks have been. It’s too soon to know what this means — it could suggest Mateen did in fact receive some training from ISIS, but it could also just be that the nightclub was really packed that night.
Foreign-directed attacks: more professional and more deadly
A foreign-directed attack is one in which leaders or key members of al-Qaeda or ISIS recruit, train, and deploy an individual or a group of individuals to carry out an attack, usually providing operational guidance (which targets to hit, how to stay under the radar and avoid getting caught before the attack, etc.) as well as resources such as money, fake travel documents, safe houses, and even weapons.
Because of the time, planning, and resources that go into these kinds of attacks, they tend to be much more sophisticated. They usually focus on more secure, well-defended, highly symbolic targets that are harder to attack, may involve near-simultaneous attacks on multiple locations, and tend to kill a high number of people and do a lot of physical damage to property.
The 9/11 attacks are the ultimate example of this kind of attack. The terrorists struck two major symbolic targets — the World Trade Center and the Pentagon (and would have struck a third, the US Capitol, had Flight 93 not crashed in Pennsylvania) — almost simultaneously; killed almost 3,000 people; and caused nearly $2 trillion in damages and other costs. The attacks in Paris, which killed 130, are another example of this, and show just how much deadlier and more destructive such attacks can be.
But these kinds of attacks, because they require so much coordination and planning, also give law enforcement and intelligence agencies — which greatly expanded their resources and capabilities after 9/11 — many more opportunities to discover and stop the plots before they're launched.
As the Paris attacks showed, they do sometimes still succeed, but many such plots are foiled. And foiled plots are costly for the groups behind them, which usually sink lots of time, money, and other valuable resources into them.
What the difference tells us about the terrorism threat
Homegrown attacks are often less deadly, which in some ways makes them less scary. On the other hand, they can be more frequent because they don't take very long to plan. They are also much harder to prevent, because they usually involve only a small number of people (or even just one person).
Since there is often no direct foreign communication, travel, or money transfers, there is not much for intelligence and law enforcement agencies to pick up on. In other words, there are fewer spots along the path from radicalization to execution of an attack for the plot to be disrupted.
Foreign-directed attacks, on the other hand, are much deadlier, as the 9/11 example clearly shows. This makes them much more menacing but also much less frequent, because they take such a long time to plan (the 9/11 attacks were years in the making). They are also easier to prevent, especially with the intelligence and security measures put in place after 9/11.
Large, coordinated attacks involve many more people communicating with one another in different countries and traveling across (often tightly controlled) borders. All this means there are a lot more opportunities for intelligence and law enforcement agencies to disrupt the plot before an attack can be carried out.
Thus, while spectacular and large-scale attacks like 9/11 are becoming less of a threat, we are likely to continue experiencing smaller-scale, yet still deadly, lone wolf–style attacks for the foreseeable future.
In fact, it is in part because post-9/11 security and intelligence measures have been so successful at preventing similarly large-scale attacks that groups like ISIS and al-Qaeda have begun calling on people in the West to carry out terrorist attacks on their own. Groups like ISIS and al-Qaeda do want homegrown attacks and actively seek to cultivate them — but it's not their first choice. If they could pull off an attack on the scale of 9/11 easily, they would.
So although it seems scary to have more of these smaller-scale attacks, it's important to understand that this is a sign we're doing a good job of preventing 9/11-level attacks. And that's something, at least.