Not sure why this is downvoted - this is absolutely correct. A lot of AWS services under the hood depend on others, and especially us-east-1 is often used for

Not sure why this is downvoted - this is absolutely correct. A lot of AWS services under the hood depend on others, and especially us-east-1 is often used for things that require strong consistency like AWS console logins/etc (where you absolutely don't want a changed password or revoked session to remain valid in other regions because of eventual consistency).