“Russia has just invaded the Ukraine”
False.
1) Crimea is NOT Ukraine, but an autonomous republic, with its own government, prime minister, parliment and budget.
2) The official agreement on the Russian navy base in Crimea stipulate that Russia can have as many as 25,000 troops there.
Last year, Russia had some 17,000. Since then it sent some 6,000 more.
3) On 30 March, the government of Crimea organise a referendum of the population on the future statute of Crimea. The will of the people must be respected by ALL.
As I understand it, the Autonomous Republic of Crimea is an autonomous parliamentary republic within Ukraine and is governed by the Constitution of Crimea in accordance with the laws of Ukraine.
I'll be the first to say I don't know Jack about Crimea but it looks like its time to learn.