Tell me, Bob: if Mexico joins BRICS (they are already in talks) and then decides to form a military alliance with Russia and/or China, under which they agree to station Russian and/or Chinese nuclear missiles in Tijuana and Juarez, do you think the US will just keep mum and swallow hard and say, "OK, I guess you have sovereignty and it is your right to sign a military alliance with whomever you want" --????

Or do you think the US would argue that they have a right not to have Russian nukes on their border?

I look forward to your answer - if you can type whilst crossing your fingers behind your back ....