Nonsense. Total rubbish. Sometimes I wish we could use stronger language here, because what I'm thinking is a whole lot stronger than what I'm able to post.
Let me put it this way. If your statement quoted above was physical trash, I'd consider it too poisonous for my local landfill. I'd have to burn it.
Quite simply: If we had invaded Afganistan ahead of time we would have been on a war footing, mking 9/11 much less likely. The South attacked the North to begin the Civil War. The logic is the same.