Why doesn't Russia simply state that a war against 30 nations is an existential threat that justifies the full use of its military, to include nuclear weapons?

I believe they already have, and Western media portrayed it as "Madman Putin Must Be Stopped - Threatens to Destroy World With Nuclear Weapons".

Why doesn't Russia simply state that a war against 30 nations is an existential threat that justifies the full use of its military, to include nuclear weapons?

I believe they already have, and Western media portrayed it as "Madman Putin Must Be Stopped - Threatens to Destroy World With Nuclear Weapons".