If we stopped using Ukraine to pester the Russians and it accepts the fact Crimea nor Donbass are going to be part of Ukraine again, there would be no threat of war. The Russians might even agree to some sort of compensation package in that scenario.
A better solution would be to return Lemberg and its hinterlands to Austria.
They can join the EU, they can have gay pride parades, they can go to Davos, the can be HAPPY - and the rest of the region can rejoin the motherland.