The Legitimacy of Violence as a Political Act?
Noam Chomsky debates with Hannah Arendt, Susan Sontag, et al.
December 15, 1967
ROBERT B. SILVERS: ... Under what conditions, if any, can violent action be said to be "legitimate"? ...
NOAM CHOMSKY: My general feeling is that this kind of question can't be answered in a meaningful way when it's abstracted from the context of particular historical concrete circumstances.
Any rational person would agree that violence is not legitimate unless the consequences of such action are to eliminate a still greater evil. Now there are people of course who go much further and say that one must oppose violence in general, quite apart from any possible consequences. I think that such a person is asserting one of two things. Either he's saying that the resort to violence is illegitimate even if the consequences are to eliminate a greater evil; or he's saying that under no conceivable circumstances will the consequences ever be such as to eliminate a greater evil. The second of these is a factual assumption and it's almost certainly false. One can easily imagine and find circumstances in which violence does eliminate a greater evil. As to the first, it's a kind of irreducible moral judgment that one should not resort to violence even if it would eliminate a greater evil. And these judgments are very hard to argue. I can only say that to me it seems like an immoral judgment.
Now there is a tendency to assume that a stand based on an absolute moral judgment shows high principle in a way that's not shown in a stand taken on what are disparagingly referred to as "tactical grounds." I think this is a pretty dubious assumption. If tactics involves a calculation of the human cost of various actions, then tactical considerations are actually the only considerations that have a moral quality to them. So I can't accept a general and absolute opposition to violence, only that resort to violence is illegitimate unless the consequences are to eliminate a greater evil.
http://www.chomsky.info/debates/19671215.htm