I was not fond of the JDL, but Rabbi Kahane Z”L was a visionary. Do you think he WANTED violence on top of violence? He wanted the Arabs out of E”Y, hopefully by peaceful means (buying up their property or offering them monetary incentives to leave), but if they were to respons with violence, he was in favor of hitting back twice as hard. And he was right.
I am not a violent person, but there was a time when Arabs were afraid to strike at Jews in Israel. It was a brief time, granted, but it was because they knew what would happen if they did anything. It lasted between 1967 and 1973. I was in seminary in 1970-71 and I was NEVER afraid to walk anywhere alone at night, and even through the Arab shuk on the way to the Kotel. Now, I feel as though the Arabs have no fear whatsoever of reprisals, To come into a SHUL and attack peaceful people while they are in Tallis and Tefillin, shows a singular lack of humanity. To slit the throat of a newborn baby and her entire family, or three young men on their way home from Yeshivah, people who clearly posed no threat to them, takes a very special kind of sick rishus. Rabbi Kahane would have had a response to those barbaric acts of terrorism.
He might have had his flaws as ALL human beings do, but his zeal and love for E”Y and Klal Yisroel, were honest and should not be disparaged. As far as I know, he did not condone unwarranted violence as a solution. And if he had followers who went to extremes, that happens in virtually every group where there is a charismatic leader. Look at what some people will do in the name of their rebbe. Should the rebbe be blamed for their being a lunatic fringe?