For 2.5 generations Crimea has been “Ukrainian” according to political maps, following Nikita Khrushchev’s unilateral gift to purchase Ukrainian political support for his succession after Stalin.
But ethnically and in reality, it was and is Russian, before and after Khrushchev’s big bribe, which was then a USSR internal political matter.
Do not mistake those that speak Russian in the eastern Ukraine and the Crimea for those who want to be part of Russia. Many Ukraininans speak Russian but do not want to be part of Russia.