Unfortunately, at the end of the day you have to fight the enemy on THEIR terms.
For an example a little closer to home in both geography and time, look into the USA, 1919, and the so called “anarchist summer”. People were blowing things up, blowing themselves up* - and yet it all ended. And it wasn't because we sat down and talked with anybody, or we tried to understand them, etc. Picking up the family of a dead anarchist, putting them on a boat, dumping them into a foreign country and saying, "stay the F out" was not timely or moral - but it damm sure worked!
*Eleanor and Franklin Roosevelt (then Secretary of the Navy and pre polio) spent an evening picking glass out of the floor of their front room after an anarchist blew himself up across the street in front of the home of the Chief Justice of the Supreme Court.
Nearly all of those warrants were overturned as being illegal, weren't they? If I recall correctly, the bombings continued even after the raids & deportations (wasn't the Wall Street bombing the biggest up to that point) but then fizzled away as they got little reaction...and as they created that monster we had to fight from 1941-1945.
And, of course, Palmer looked like an overreacting fool.
And it hurts us today, just like the little boy who cried wolf.
Unfortunately, at the end of the day you have to fight the enemy on THEIR terms.
Only the fool fights fire with fire. The wise man fights fire with a fire extinguisher.
All that being said, I am taking issue addressing only the specific ways you put it. It could very well be that genocide is the answer (though I'm not so sure it is).