Pierre, please tell us where you live? You obviously would have no problem with 7.5 Billion people removed from the map.
If I'm not mistaken, we all die. The question is how to live well, and that means not giving in to some tinpot murderous dictator like Putin who thinks he can restore the 19th century great power politics that brought us both WWI and WWII. Giving in would be far more dangerous.
If Trump were in office this war would never have taken place. The US is not aiming to destroy Russia or even to remove Putin despite all the hyperbole. Merely to defeat the latest Russian invasion of Ukraine. Russia is not going to use nukes for the simple reason that the US has 10 nuke warheads for every Russian city over 50k in population, with a few hundred left over for China.