What war crimes? All is fair in love and war ... or if your country does something in war.
The holy grail bio war weapon like weaponizing the common cold seems to have killed millions. So whats the big deal in killing 500 million people in an accidental nuclear exchange. When an outcome is not a zero possibility, it will happen. Investing in 40,000 nuclear weapons is not zero.

Dresden, Hiroshima and Soviet Union will be the minor examples of the numbers of war casualties. We are all statistics now, waiting for when -

not if.