It is interesting when you watch native animals fighting, the winner is often decided very early, as soon as superiority is established, one side retires with minimal damage
The human species don't do this usually as the leaders stay in their bunker, safe
Diplomacy is not a skill taught to any leaders for the same reason, they are not on the ground in the front line.
It is a simple equation, every man and his dog knew this was going to happen, so either pour help into Ukraine in such large numbers as to stop it happening, or work out a solution, the solution in the short term is easy
Make certain that the Ukraine is specifically a neutral country with no military assistance from either side
