The same thing we did the last time Russia invaded one of her southern neighbors and attempted to annex it: Supply them with weapons.
In this particular incident we actually signed an agreement “assuring” borders and sovereignty. We should live up to that agreement, since the Ukes lived up to it.
https://en.wikipedia.org/wiki/Budapest_Memorandum_on_Security_Assurances
1. ‘k , we are supplying them with weapons.
2. “ “We” should live up to that agreement.”
How exactly?