Is the Van Allen belt a purpose built quarantine field?

I have read a few times that the earth is held under a secret quarantine by some force for some reason. also, anti moon landings theorists suggest that the radiation from the Van Allen belt is proof we never landed on the moon. what if the Van Allen belt is a purpose built field or shield that was switched off just long enough to let Apollo through. That something put it there on purpose. it might even protect us. just a theory. lol