Where Islam is discussed, controversy follows.

Though the 9/11 attacks by Islamic extremists are almost 10 years past and al-Qaida boss Osama bin Laden is dead, the American debate over Islam is still raging, as evidenced by numerous conflicts over public events around the country.

The battles — a kind of holy war for American hearts and minds — feature a changing cast of players, but they typically array some of the dozens of groups dedicated to exposing the threat of radical Islam in the U.S. against dozens of others established to protect the rights of Muslim Americans and defend their religion as peaceful.

Charles Kurzman, a professor of sociology at the University of North Carolina at Chapel Hill, says the clashes over Islam point to two powerful prevailing currents.

“One trend is heightened alarm and suspicion on the part of people concerned about domestic security,” he said. “The other trend is increased assertiveness and political activism on the part of Muslim Americans.”

At a national level, the conflict played out in controversial congressional hearings in April, which featured testimony from witnesses warning of a threat posed by Islamic radicals within the United States. Meanwhile Muslim leaders and civil rights groups — who were largely excluded from the proceedings — held press briefings comparing the hearings to red-baiting of the McCarthy era.