From Longman Dictionary of Contemporary Englishmight is rightmight is rightBritish English, might makes right American EnglishPOWER used to say that powerful people and countries are able to do whatever they want, especially when you disapprove of this → might
Examples from the Corpus
might is right• Second, we need some kind of global bodies to prevent a further slide into a politics of might is right.• What the child learns is that might is right. 