This is Crimea 2.0. The ideological basis behind the annexation is identical in both instances.
Honestly, as someone who firmly opposes what Putin did, there were better "historical justifications" for Russia to annex Crimea than for the USA to colonize Greenland, a territory that has never been part of the USA. The idea of invading an ally's territory just to steal its resources is particularly shameful and disgusting.
It actually reminds me more of the Falklands War...