There is a lot more to a communication system than the primitives it uses. Even holding primitives constant, there is a lot of room for variation (and bugs and side channels). Recall that one of the early identifiers of equation group was subtracting 0x61C88647 rather than adding 0x9E3779B9 during RC6 key setup [1 p. 28]. So I guess what I'm saying is nations don't just download AES bitstreams off the internet.
I am fairly certain most of the western world relies on a Belgian cipher called Rijndael to encrypt all/the majority of its diplomatic communications.
I'm not really sure what you mean by this comment.