Biodegradeable WMDs

Imagine a world where the so called 'WMDs' that all these world powers are believed to have. the amount of power they hold in the palm of there hand to be unleashed with one word one push of a button and the whole of the world would be plunged into chaos and all that was left was a mass of pure destruction and charred trees some still burning. After millions of years the earth has settled and all is at rest.

Now imagine that those WMDs were actually made out of sprouts and turnips. I think that the world would be a lot better of if instead of using weapons that cause destruction, they can still kill as that is the whole point of 'weapons', but when they do kill they fertilize the ground afterwards. 'The considerate weapon' it could be called. A nuclear holocaust would never be seen in the same light again. Granted It would really hum afterwards but the ground would be all fertilized and not full of shit. there would be a lot of blood and guts but that would just turn to a mushy pulp and ad to the ground. Green Peace would have a field day!