"States are sovereign. Borders cannot be changed by force. Those principles are not new. Nor is there any ambiguity to them.

The ... problem was never the rules themselves, but Russia’s decision to disregard them."

https://www.gov.uk/government/speeches/russias-history-of-disregarding-the-sovereignty-and-territorial-integrity-of-its-neighbours-uk-statement-to-the-osce

#Ukraine