Russia's other recent international seizure was Crimea, which was for sure NOT done in accordance with the International Law of the Sea. Canada has, in fact, enacted sanctions against Russia. I posit that if Canada were a softer target, Russia would simply seize the territories, the way they did from the Ukraine.
Interestingly, this convention is signed and ratified basically by the whole world, but not by the US.
[0] https://thebarentsobserver.com/en/arctic/2019/04/russia-scor...
[1] https://en.wikipedia.org/wiki/United_Nations_Convention_on_t...