The only way is to try to insulate oneself from these radicals by not letting them immigrate, or if it doesn't help pick an area controlled by the most vicious of these radicals (ISIS territory comes to mind) and give them a taste of what armageddon could look like so they'll learn an important lesson.
This has worked very well in the Chechen wars. The Russians tried negotiating, then they tried having a series of smaller military operations in order to take out their leaders. Then the Russians even conceded and gave them defacto independence, but It all didn't work. They instead went on to attack neighbouring Russian states and then even killed hundreds of Russian children in the Beslan terror attacks.
What did help though was Putins response completely levelling the Chechen capital Grozny. And I mean that literally because that's what they did. After that 99.99% of them became cooperative, in fact today most Chechens in Chechnya consider themselves fierce Russian patriots. I wonder why!