Violence is arguably most effective. However, seeing as how it is illegal, I'd opt for civil disobedience.

It's circumstantial. You cannot use civil disobedience against strong forces such as the Tali ban. You cannot march into Iraq or Afghanistan with peace signs saying "Hey, lets end the war! Deal?" To get rid of the people who constantly killing people in large quantities through violence will be more effective because you end up wiping them off the face of this planet so that they cant harm anyone. Of course there are others out there who will be worse or equally as bad, but that happens with any case. There is logical violence which you use because you have a cause and you're trying to end something, and then there is pointless violence such as the one that the children of Palestine impose on the Israeli soldiers.