I understand completely.
The current circumstances aren’t the same. Events are still manageable if they had the will.
What is war but failed diplomacy?
Economic pressure is the proper method. Tell Russia that they would be financially responsible for any area they would annex. The IMF loaned Ukraine $18B and since Crimea is still recognized as sovereign territory, Russia would have to pay proportionally.
What is war but failed diplomacy?
"War is regarded as nothing but the continuation of state policy with other means." von Clausewitz
War is not failed diplomacy. Some nations use war as an instrument of policy to achieve national objectives.