(CNN)ISIS may have claimed the Westminster attacker was one of its soldiers, but a UK official tells CNN it is too early to say whether attacker Khalid Masood had operational links to ISIS. Many are speculating he was a "lone wolf."
Analysis: Don't bet on London attacker being lone wolf
This term is generally used to denote plotters who have had no contact with any established terrorist organization. It can refer to a single individual plotting an attack like the Orlando shooter or multiple individuals plotting an attack like the married couple behind the San Bernardino attack. Both those attacks were inspired by ISIS but saw no contact whatsoever with the group. The Boston bombers were also most likely lone wolves.
It's a bit of a misleading term because lone-wolf plotters can conspire in packs and are very seldom solitary. Extremely few terrorists plots are carried out by individuals who are true loners. Terrorism researchers have found that almost all those who have become engaged in terrorist activity are friends with like-minded individuals in person or online.
But we seem to be stuck with the term. So it's worth asking whether the current threat wave against Europe is being driven by "lone-wolf terrorism."
The answer is a resounding no.
According to researchers at the Norwegian Defense Research Establishment, of the 42 Islamist terrorist plots in Europe between 2014 and 2016, approximately three-quarters involved plotters directed by ISIS operatives they met in person or over the Internet. They found there were only six plots in which individuals were lone wolves inspired by ISIS.
They found that 12 plots, including the Paris and Brussels attacks, involved foreign fighters dispatched to Europe.
And they found that a stunning 19 plots had European plotters receiving online instruction from individuals who were part of ISIS. A recent likely case in point was Berlin truck attacker Anis Amri, who is believed to have been in touch via encryption apps with ISIS operatives in Libya.
That suggests ISIS is driving the current wave of terrorism in Europe. The game changer has been the group's use of encryption apps to encourage and guide attacks in the West without being detected. They've used these methods both to coordinate attack cells they have sent back to Europe and to remotely control plotters they have never met in person.
Seamus Hughes and Alexander Meleagrou-Hitchens, researchers at the George Washington University program on extremism, have dubbed the ISIS operatives remotely instigating these attacks "ISIS virtual entrepreneurs." Operating from places like Raqqa in Syria, they tend to speak the same language as those they are reaching out to in the West. Two notorious examples were French ISIS recruit Rachid Kassim and British ISIS recruit Junaid Hussain, who were both killed in coalition strikes.
In a research paper published by CTC Sentinel, the researchers found that eight out of the 38 plots in the United States after 2014 saw the involvement of such virtual ISIS entrepreneurs.
There have been no plots in the United States in which ISIS has dispatched operatives trained in "caliphate" territory.
That means the threat in the United States is the inverse of that in Europe: 79% of plots in the United States since 2014 have involved lone-wolf terrorists.
One reason is that many fewer Americans have traveled to Syria and Iraq than Europeans, offering the group fewer opportunities to dispatch Americans back home to launch attacks. It may also be a bit more difficult for Americans to establish contact with ISIS operatives over the Internet because there are fewer Americans in "caliphate" territory.
Another possible reason is that the high number of "sting" operations by the FBI have inflated the number of lone-wolf plots. If you're an extremist you may not feel quite the need to reach out to someone who is actually in ISIS if you are communicating with someone you think is part of ISIS but in reality is working for the FBI.
What's clear is that plots directed over the Internet are becoming increasingly common on both sides of the Atlantic.
Don't bet on the London attacker being a lone wolf.