OMG. Are you kidding me? Let them slug it out! That will lead to a nuclear World War III. All those atomic bombs exploding will put so much debris in the air it will cause a "nuclear winter" and reduce the amount of sunlight coming to the earth for many years. We will have frost every month of the year. Thus it will be impossible to grow crops and the human race will slowly starve to death.

https://en.wikipedia.org/wiki/Nuclear_winter