Obama needs to call these people what they really are...cowards. cutting off a handcuffed guys head takes no balls or "power" or "strength" at all. Suicide bombers are a passive aggressive pansy way to fight. Be 1/2 the man you think you are and fight straight-up. Be real or GTFO!
I'd tell that fuck straight up, put the knife down or better yet, keep it in hand and fight one of our guys hand to hand with a knife in his. Otherwise crawl back to your caves and be the cowards you are and enjoy playing tough-guy bit on video hiding like trolls. The reality is you are anything but the role you are trying to play. Terrorists everywhere you are all pussys and keyboard warriors. Even the fucking Russians are rolling in with a fight, even though Putin won't come out and own-it. They are at least committed and willing to put up in the face of what they want.
He should say that, drop the mic and let the press stand astonished that he actually said it.