Would it be futile? I suppose it depends on your goal. If you're trying to eliminate terrorism, then you can't do so by committing terrorism. If you're trying to prevent a particular group of people from engaging in terrorism, then I disagree - I think that killing them indiscriminately is probably expedient and effective.

Who used terrorism against the Nazis? To a very small degree, German Jews... but mostly, the Czechs, the French, and German Christians were responsible for almost all of the clandestine internal resistance faced by the Nazis. Why is that? Because Jews are inherently docile? I don't believe that for a second. Rather, I think it was because the Jews were being exterminated, a precondition that makes it difficult to fight back.

Financial restrictions probably work well against well-funded guerrillas... the Iraqi insurgency, or Hezbollah, which are both heavily equipped and funded by Iran would lose a lot of their ability to harass the American and Israeli militaries respectively if their money was taken away... but according to Todd Sandler, a University of Texas "expert in transnational terrorism", a suicide vest costs $150. I suspect that taking away expensive things like explosively-formed penetrators and radio detonators from the Insurgency would just make them go low-tech, at which point they would start targeting civilians more.

To be clear, I don't like State-sponsored anything, let alone violence; I'm a strident anarchist. I do think though that things could be an awful lot worse. The present is actually a fantastic time to be alive (when compared with a non-nostalgic understanding of the past).