I have zero ethical issues with what breivik did.
I just accuse him of making a strategic blunder. Obviously it did not stop immigration. It was pretty stupid of him to think it might.
I'll disavow the guy if you want me to. Just not for the reasons you want me to.
I agree that Norway should remain Norway. And people who want to commit genocide against Norwegians should die. I agree with him completely about that.
Hopefully someday the Norwegians will have the ability to manifest such justice. They just don't yet. He was too idealistic.