I am not sure that gun or knife control can ever stop terrorism. What gun control does is make it harder for crazy people to get guns and do random killing.
I am positive that weapons control most certainly can not ever stop terrorism, or any crime. Terrorists don't care about the law now, do they? ;) Neither do everyday garden variety criminals.
Nor does it make it any more difficult for crazy people to get guns. It only makes it more difficult for them (or anyone else) buy them legally.
Weapons (not just gun) control is only about control and power. It always has been so, and always will be. Ever since the first chieftain forced his cavemates to give up their clubs and stone knives so that he could take the largest portion of the deer meat, the "rulers" have demanded disarmed plebes so that they can do as they please without consequence. All throughout history, the only people that enjoyed freedom were armed. See the point?