Everywhere one looks these days, it seems that global norms are under assault. From the South China Sea to Eastern Europe, longstanding international rules of the road — concepts such as non-aggression, freedom of navigation and self-determination — are being flagrantly flouted or subtly eroded. Ideas, such as democracy and respect for human rights, that seemed to have become incontestably dominant are facing renewed threats.

Americans and people around the globe are getting a harsh reminder of a truth that is too easily forgotten — that the whole idea of global norms is an illusion.