so Crimea held a vote and they voted to go back to Russia in 2014 after the Ukrainian government got overthrown by neo Nazis and they started ethnically cleansing eastern Ukraine.

Two other Ukrainian regions in the East also voted and decided to become independent countries.

that's when the Ukrainian civil war started.

calling it a Russian invasion is misleading. Russia only entered Crimea after they democratically decided to leave Ukraine and go back to Russia.