Labels matter in the fight against terrorism. Many U.S. officials insist on using the term “radical Islamic terrorism,” the imprecise phrase does more harm than good. First, terrorism by its nature is radical, so “radical terrorism” is redundant. Second, using “Islamic” (which means “of or like Islam”) and “Islamist” interchangeably offends billions of peaceful Muslims and lends legitimacy to terrorists’ claims that their actions are justified by religion. Simply using precision in describing the problem — “Islamist terrorism” — does a great deal to avoid alienating potential allies in the Muslim world and puts the focus on those who commit politically motivated acts of violence using a veneer of faith.