Russia won't start WWIII because of the weapons.
1. In conventional warfare, they have 0 chance against NATO. Also, they have 0 allies who are willing to join them.
2. In nuclear warfare there are no winners (though I am a bit skeptical now about Russians nuclear might), but I don't think there is a measurable probability of nuclear war.
Also, at the end of the day, after the war is over, the whole world should think how great is to have a big country that threatens nuclear destruction every time its gas pipeline to Germany gets postponed.