Or what would happen if something like it would happen today.

Russia is pretty much nazi now (superior Russian genes and soul + genocide of Ukrainians) and they are not exactly swinging them but definitely sabre rattlin.

Israel is not using theirs on Gaza either.

Russia does not use nukes because the US and EU exists as deterrents.

Also there's a reasonable chance that some of them won't work correctly which will then weaken Russia's show of strength

To be clear I'm referring to a new superweapon or defence scheme being invented that somehow makes nukes obsolete.

Imagine what Trump would do. He is already trying (and mostly failing) to strong-arm all his allies today.