Crimea has been part of Russia for hundreds of years. It is home to its Black Sea navy. It is overwhelming Russian speaking. There was a plebiscite in 2014 with approximately 90% of the population voting to return to Russia. There was little to no resistance when Russia annexed it in 2014.
“There was a plebiscite in 2014 with approximately 90% of the population voting to return to Russia.”
Anyone in Crimea who wanted to return to Russia simply had to cross the border into Russia. But they aren’t allowed to bring Crimea with them as if it were a steamer trunk. BTW: The Ukrainian constitution addressed such referenda; and it stated that ALL Ukrainians had the right to vote in such referenda, not just those is the affected area. Russia squawked at that, disregarded it, and invaded.
“There was little to no resistance when Russia annexed it in 2014.”
That is actually irrelevant: It was an invasion of another sovereign and independent country.