Someone needs a new translator.
It was because of MAD that the old USSR did not dare directly attack the USA (and now China too). That’s what Sarah has in mind, and she means the USA needs to act because if it won’t nobody else will.
I hope Russia keeps some sense of history. America will not brook Barack Obama to be its president forever. If tit for tat is all Russia can think to play, tit for tat will be the game it gets.