Scientists need to look at how to disarm and dispose of nuclear, and come up with alternative clean energies.... As for the weapons, make peace not war. If we could genuinely try alternative negotiation strategies, and change our arrogant political systems, then perhaps we would need to invent new weapons!
There are about 15,000 nuclear weapons in existence today. What can you do with it? Throw it all into the ocean? Once you make it, there is no going back. Most people aren't aware about the number of nuclear bombs available. There is literally instructions on how to make a fully functioning nuclear bomb on the internet. (obviously not everyone has the 'ingredients' required to make one though)