If there have been biological and nuclear weapons of mass destruction 88 years ago, they would have been included in the Geneva Convention along side of chemical weapons.
After the indiscriminate abuse of nuclear weapons in Hiroshima and Nagasaki, that made any deaths by chemical weapons look like a Sunday picnic, the Geneva Convention should have been reconvened and list nuclear weapons of mass destruction every bit as bad and cruel and despicable as chemical weapons.
Of course, by then the biggest dog in the fight was the dog that dropped the atomic bombs on innocent women and children, so the signatories of the Geneva Convention, to this present day, decided that Saddam Hussain, Adolph Hitler and Bashir al Assad are bad, but the one who killed more and more painfully - and for many years - than all three of these combined, you know, Harry Truman, is good.
They decided that the buck should stop right there.
Unless the Geneva Convention includes biological and nuclear weapons of mass destruction, all the huff and puff about chemical weapons of mass destruction is meaningless politically correct mindless babble.