I agree with your opinion.
But the problem is that: every option in your comment is a long term policy, it can't resolve the current problem in the reality as quick as possible.
Freedom is not free.
The majority of world are like peace, but the minority can break it with terrorist attacks.
To prevent the attacks, the majority will pay a huge price.
In the other way, the minority's attacks will create Nationalism in the majority, and this will make the attacks more worse.