But the speech - intended to reassure a nervous nation - didn't announce an overhaul of a policy that critics have branded insufficient to take on the evolving threat.
Obama, speaking in the symbolic surroundings of the Oval Office, unequivocally told millions of television viewers in prime-time that last week's mass shooting in San Bernardino, California, was a terrorist attack by a couple who had gone down the "dark path of radicalization" and embraced a "perverted" form of Islam.
"This was an act of terrorism designed to kill innocent people," Obama said. "Here's what I want you to know. The threat from terrorism is real, but we will overcome it. We will destroy ISIL and any other organization that tries to harm us."
