With the most recent killing of an American journalist, Steven Sotloff, the Islamic State in Iraq and Syria, or ISIS, is doing more than simply trying to scare the United States out of bombing the group, says terror psychologist Anthony Lemieux. They’re doing it for expansion purposes.

“The beheading [of Sotloff] is further evidence of their efforts to gain attention of Western audiences,” says Lemieux, an adjunct professor in Emory’s School of Medicine and Rollins School of Public Health and associate professor of communication at Georgia State University. “ISIS is also working to exacerbate the conflict and draw the U.S. in further.”

This is all part of ISIS’s growth plan, not just in territory but also by bringing sympathizers to their cause, Lemieux says. “The group has involved and targeted Western audiences with their communications,” he explains. “They have established a fairly well-developed media creation capability, which is exemplified through both their video releases as well as their English language materials.”

The terrorist organization Al-Shabaab is acting similarly with media and social media efforts to reach and influence Western audiences, says Lemieux. The group has an online magazine, “Gaidi Mtaani,” which means “terrorist on the street,” and includes both English and Swahili.

“The American strikes against core leadership recently may influence the scope and focus of their operations going forward, but it also may influence their receptivity to foreign fighters traveling to join their ranks.”