Dude we know. That’s why it was so stupid to overthrow a democratically elected government that was friendly to Russia. This is a predictable reaction. There is nothing we can do that will stop it except working out a grand bargain.
Russia is sending a message about how they will react to things like this. We can respond to that in various ways, but can’t act surprised. Obviously, our leaders did not have a back up plan.
Now, the Ukrainians must prepare for asymmetrical war. They must be ready to attack Soviet ...er, Russians upon invasion.
Attack their supply lines. Burn anything not guarded. Force them to commit masses of troops.
Plant real and fake mines along invasion routes.
Prepare snipers to shoot and kill them without getting caught.
Prepare to assist any Russian wanting to escape this rich man's war of Putin's and this poor man's fight. Help them escape to the West until the invasion ends.
Destroy bridges ahead of their advance.
Destroy and burn fuel points and ammunition with fires.
Make them pay a huge price in men and materiel.