Arrests in separate terror plots in Springfield, Ill., and Dallas Thursday followed the indictment of Najibullah Zazi for plotting an attack in New York. Experts say the cases highlight the danger of domestic terrorism.
In less than a week, six men in five states have been charged with terrorist plots to blow up federal buildings, attack Americans, and bring about the sort of mass destruction not seen here since 9/11.
The alleged plots are separated by geography and scale, but the suspects appear to share a belief in radical jihad and be influenced by Al Qaeda in their desire to strike against the West, in particular, the US.
"What we are dealing with is this extreme fringe who believe they need to commit violence in the name of God," says Matthew Levitt, a counterterrorism expert with The Washington Institute for Near East Policy.
Arrests Thursday in Dallas and Springfield, Ill., followed on the heels of a separate investigation stretching from New York to Colorado. Some of the suspects acted alone and others in small groups, but none seemed to be part of an organized Al Qaeda cell.
Together the cases demonstrate that Americans remain vulnerable to domestic terrorism, albeit from "a tiny fraction of society," that has been radicalized by extremists operating in such places as prisons and via the Internet, says Dr. Levitt. (See a timeline of terror plots against the US since 9/11.)
The string of terrorism investigations should renew efforts to bolster counter-radicalization strategies at home, Levitt adds.
"The vast majority of the Muslim and Arab American population is well integrated and rejects this violent ideology. Unfortunately, the US government has not always empowered these communities effectively to provide an alternative to the extremist narrative," said a Washington Institute report on global counter-radicalization efforts earlier this year.