"The Holy War is here," O'Reilly said. "And unfortunately, it seems the president will be the last one to acknowledge it."
But Hayes disagreed: "I'll probably be after him, if he ever acknowledges it," the MSNBC host quipped.
Journalists and critics were quick to target O'Reilly for his comments. Vox's Max Fisher called the Fox News host's announcement "silly," "dangerous" and "alarmingly short-sighted," and accused him of granting ISIS its wish. Wednesday night, MSNBC's Hayes joined in on the counter attack.
"That sort of rhetoric is, of course, exactly what ISIS wants," he said of O'Reilly's war declaration. "For if this is a Holy War, they aren’t some murderous cult or some fringe Sunni militia. No, if it’s a Holy War, then they are the representatives of Islam, which is why the president at today's summit on countering violent extremism was so careful not to cast the fight on those terms.”