I'm not too familiar with historic international law, but most of the ones in modern use are only decades old. So, while the invasion of Hawaii may be immoral and may have broken international norms, I'm not sure if it's consider to have broken "International Law".

[–] taladar@sh.itjust.works 5 points 5 months ago

The concept of sovereign states is generally considered to be established in the Peace of Westphalia in 1648. Of course the US did not exist at the time but it was a concept established as International Law before it was founded. Of course most treaties of this kind weren't signed by nearly the same percentage of nations they are today.