If the homeless person refuses to live in the house you build for them, your project isn't going to be successful.
Basically the deal here is the world must convert entirely to fundamentalist Islam to satisfy these people, and then they'll find some reason why you don't belong to the right sect of Islam, you heretic!
Unfortunately, punishing the perpetrators will not do the job. They are very few and they expect to die with assurance they'll be in paradise anyway, and there'll be plenty more coming from where those did. These'll just be martyrs for the next wave. It will be necessary to cause unnaceptable destruction to the so called "innocents" who harbor them and celebrate their acts.
We cannot defend against them. The problem must be stopped at its source, and it can only be stopped by the people who live there. They must be given a reason to do so.
You can be sure these groups are working hard to get portable nuclear weapons. Should we just wait until they have them and blow up Washington and New York entirely?