Sounds like you need to read up on history Ski. If you read history you would know that Crimea has a long history of being very important to Russia. They have fought hard to get Crimea since way back. It is a very important place strategically for the the Russian navy.

Why should Russia be given these territories? You approach this question from the assumption that every choice in international politics must be done on the basis of what is morally right and just.

Russia should be given these territories for the same reason you would give your walled if somebody put a gun to your head.

Imagine asking the guy with the gun "But why should you have my walled exactly?"

I am the sane guy tell you to give the robber the wallet. You go: "If I do that he will just go on and rob other people. "

Sure, but deciding to stand your ground while he has a gun to your head is tactically a very bad choice. Pick your battles.

Instead what you do, is afterwards you get yourself a gun. Train and learn how to use it. Then you are ready for next time.

This is what all sane armies do. When they are about to be encircled, they don't stand their ground, they pull back and regroup.

That is what we got to do in regards to Russia. Pull back and regroup. Use the peace to re-arm, build up defenses and make sure Russia can never bully anyone again.