Economic isolation is the harshest move you can do short of direct military conflict. It may be that the right answer to military is military, but I'm okay with

Economic isolation is the harshest move you can do short of direct military conflict. It may be that the right answer to military is military, but I'm okay with sanctions as a buffer before troops on the ground. As for WW3, what kind of WW3 do you imagine? What kind of multi-system war would that be? One where China and Saudi Arabia is standing with Russia? If Russia flies nukes then they will lose what little support they have in the world.