First I think you mean imminent and not eminent
And to answer your question, war is not a sport or a competition where you need to score to win or to challenge yourself, war is about winning by force and if you are invaded or attacked you will use any means at your disposal to defend yourself and counter attack. That is why nukes will most certainly play their part should WW3 break out.
Nukes will not be use if the war break, according to war expert. Nukes exist as deterrent, and not use as weapon. Because once u use Nukes there will be no war at all.
Did you know bees die when they sting you? A bee that stings you dies cause it disembowels itself as it plunges its dart in your skin. So this is not a win for the bee, yet if you bother a bee you better believe it will not hesitate to sting you...
Nukes are indeed a deterrent but should the other side not be deterred for some reason then you better believe that nukes will be used. If you think that Russia can attack the US and that the US will do nothing about it or the US attack Russia without Russia defending itself you are missing the point. The only scenario in which things would not degenerate into WW3 and nukes being used is if somehow the two parties wage a conventional war in a localized region like in Syria. The two parties could in theory simply exchange missiles attacks inside Syria.
But should that happen you can bet your last tooth that neither party will accept being attacked by the other one without showing real teeth and that's when the threat and actual use of nukes becomes a very serious reality. At that point it's not about winning, it's about making sure the other side loses too.