Why worry, some ask, mutual assured destruction means neither the US nor Russia would initiate a nuclear attack.  Perhaps not, but the greatest danger of nuclear armageddon comes from false alarms from warning systems.  During the Cold War there were many such alarms.  The false alarms did not result in mutual destruction because both governments were working to defuse, not exacerbate, the situation, and there was time for the validity of the alarm to be verified before a fatal pushing of the button.  

Today the situation is entirely different.  Washington and the NATO puppets have a policy of provoking Russia, with the 2014 coup in Ukraine and its consequences being the worst to date.  Moreover, the hypersonic speeds of the Russian missiles and the closeness of US missiles to Russia's border cuts time before impact to 5 or 10 minutes, which means no time to verify or confer.  

The extraordinary insulting hostility shown toward Russia by the US, NATO and the Western media has convinced  the Kremlin that the West intends Russia's destruction.  Russia's President Putin has stated  many times that the West has led him to this conclusion. A couple of days ago at the Valdai Discussion Club Putin expressed concern that the West's belligerence toward Russia could end in nuclear war.  If President Biden were a responsible leader, he would have said that the Russian president is right, and we must stop the escalation of threats.  Instead, Biden sent B-2 stealth bombers, aircraft  specifically designed for a nuclear first-strike, to European bases, thus escalating the threat, a mindless and irresponsible response to President Putin.    

In the US the constant propaganda against Russia (and now China) has convinced many Americans that they face the danger of  nuclear attack.  This is not a situation in which a false alarm is likely to be recognized.  The risk of not believing the alarm is much higher in the environment created by the American neoconservatives, who have controlled US foreign policy in the 21st century.