Yes, of course. There is such a thing as 'pay them back'. But this is the beginnings of the real war.
Ordinary symmetrical measures.Russia considers Ukraine to be part of their friendly group. The little 'military playing' that they have done with the Ukraine so far, hasn't been about destruction of Ukraine. It has been about requesting Ukraine to stop their fighting and be family. It has also been about giving the Ukrainian people time to get out, or to decide to stay no matter what.
Ukraine for Russia is like a capricious infantile spoiled child. To whom everything was allowed for too long, and in 31 years he grew into a moral freak, who believes that everyone around him owes something simply because. Take a look - it's quite typical.You don't understand the major point. In fact, Europe owes Ukrainians all the things and without any conditions.
Now it's time to give the little asshole a good belt on his ass. 