>It's was not a secret that NATO's enormous expansion was dubious for the US or that european countries do not contribute nearly enough.

I think it would be useful for you to flesh out those two points. 'It's not a secret..' sounds like a Trumpist soundbite, a mechanism to try to pass off a personal opinion as fact or at least as established consensus. There are some much more eloquent people than me in this thread who have argued the exact opposite of what you have stated, that Nato is a net benefit to the US. Would you mind fleshing out your counter-argument further please