My grandfathers' bomb

My grandfather was an exteremly bright man. He was a gifted electrical engineer and mathematician. He led an interesting life and had many other interests and talents. He also had a sprightly sense of humor that lasted long into his decline. He even had a part to play in the development of our nation's Manhatten project. I do not think he ever felt comfortable discussing it, probably because no one ever told him it was alright to talk about it. But he and others united against a common threat and developed the most effective weapon ever conceived. Nuclear weapons are amazingly efficient, one plane, one missile, one bomb, one freighter has the potential to unleash the equivlent explosive power of all the ordinence exploded in the WWII (including the two atom bombs.) Although they are very complicated to build, they are fundamentally very simple. For fission, get a mass of metal at one point for a certain period of time. For fusion, expose an isotype to a very high temperature 50+Mil K. Then boom! Nuclear devices range from a 1KT device to a rumored ->1GT<- device exploded behind the moon by the Russians. Truly a marvel of science and an effective weapon. So effective that fear of their use kept two great powers in a uneasy peace for 30 years. So effective that they were used only twice to unequivocally win a war. Some might say too effective. A weapon that is effective is one that frequently achieves the desired result against a target. For a weapon that is 'too effective' to use, why do the US and Russia still have pile and piles of them?
stockpile
Cost of them

What possible contingency can there be to support these astronomical numbers? There is plenty of evidence to support the fact there is at least a desire to reduce the stockpile to below 'armeggedon' levels. From what I have read, the main problem is that neither party is willing to make the first move. I believe that is time for the two gunfighters of the cold war to finally blink and standdown and start applying the astonomical costs of maintaining these specters to other means. My late grandfather would agree I think.