The West attempted again and again to establish a rule of international law and its institutions, and to empower them. Most successes of these efforts came in the era since 1944, most of them associated with the United Nations or the European Community/Union.
The restrictions imposed on government's freedom of action is unpopular among them, though. Great powers eroded and evaded the rule of law thus and established a rule of force for themselves. Even small powers did so - the EU stability pact was such an example where a treaty was eroded because of tolerated violations by both small and great powers.
We have the prospect that the traditional great powers will become less powerful in relation to the rest of the world and they might actually benefit more from a rule of (international) law than ever before - but it's probably too late. They worked hard on ruining their own concept. To demand adherence to a concept they hypocritically ignored at will will be understood to be an expression of even more hypocrisy.
The exceptions to the rule of (international) law have been established as common for great powers, and future great powers will likely exploit this to their liking.
|(A probably too light-hearted illustration)|