Non-military deterrents:
How about turning off Moscow’s lights for a few hours? Or wider-scale?
Or seizing ALL Russian assets in the West?
Darker deterrent:
Seize all children of Putin & Russian generals & elite who reside or school or vacation in the West?
—O.S.
Without a doubt, it’s not how democracies would want to be seen or what they would want to have to defend in courts or justify to their public. However, it just might bring much closer to the homes of the decision makers the price of launching nukes & help ratchet down that existential risk of global thermonuclear war. —OS