Although he is biased to minimize the threat, his research is well done. In his latest report, Muslim-American Involvement with Violent Extremism, 2001-2018, he documents that "Fourteen Muslim-Americans were arrested for alleged involvement with violent extremism in 2018, the lowest total in a decade. The wave of Muslim-Americans associating themselves with the self-proclaimed “Islamic State” appears to have dwindled (see Figure 1)."
Figure 1 shows a dramatic drop in Muslim Americans arrested for terror or extremism:
He asks a number of experts why they believe that these numbers have been going down so sharply since 2015. The responses are generally thoughtful and seem on target - and also help explain why the numbers from 2012 to 2015 increased so dramatically as well.
The most common theme in the researchers’ responses involved the Islamic State’s loss of territory. Peter Bergen, a journalist and director of the national security studies program at the New America Foundation in Washington, D.C., suggested: “While correlation is not causation, it’s striking how these figures correlate with the rise and fall of the physical ISIS caliphate. That supposedly perfect Islamist society was a powerful pull factor in attracting idealistic young Muslim men and women from around the globe, including to a relatively small degree in the United States, to either join ISIS or attempt to join ISIS or to try and carry out attacks in ISIS’s name.”ISIS' losses of land, combined with vigorous monitoring and removal of pro-terrorist social media sites, seem to be the major factors in fighting Muslim American terrorism, because the cause itself is no longer seen as a "winner." That can change quickly, as some of the experts note.
David Schanzer, director of the Triangle Center on Terrorism and Homeland Security at Duke University, noted that “the incidence of violence by extremist Muslim-Americans rises when foreign insurgent movements are successful – that is, they are gaining territory, they are making claims to be an authentic alternative Islamist society, and they are pushing this message aggressively through
social media. When they are ascendant in this way, their call for like-minded diaspora Muslims to 'do something’ can be compelling to at least a small cohort of Muslim Americans. When these movements don’t seem to be doing much themselves, their use of guilt or shame to compel violence by diaspora Muslims loses its bite, as has been the case as ISIS has gradually lost its so-called caliphate over the past 4 years.”
Along with the Islamic State’s loss of territory, several researchers commented on its loss of online recruitment capabilities. Seamus Hughes, deputy director of the Program on Extremism at George Washington University, commented: “The death of key online recruiters such as Junaid Hussain and Abu Saad al-Sudani, who were killed by airstrikes, played a role in numbers going down. It is hard to facilitate travel if there are no easily accessible online facilitators.” ... J.M. Berger, a research fellow with VOX-Pol, a European academic research network, suggested that online recruitment was particularly important for militants in the United States: “We’ve seen a major crackdown on jihadist social media and Internet presence. While I don’t want to be too aggressive in attributing causality there, it is pretty likely that this has helped depress both recruitment and the virtual/remote direction of attacks, especially relative to Europe, where there are more robust offline extremist social networks."
Seth Jones, director of the Transnational Threats Project at the Center for Strategic and International Studies in Washington, argued that “terrorism is an inherently non-linear threat. Surprise and shock are the terrorists’ age-old stock and trade. If it were predictable, terrorism would lose the power that makes it the preferred tactic of America’s most intractable enemies. So one should not assume that the levels of Islamist extremism violence will continue to decline.”
Also notable is that many of the people who were arrested were discovered before they managed to even get close to performing the terror acts they intended.
This means that the FBI has been remarkably effective at monitoring and disrupting Muslim-American terror attacks, something I have noted before.