I would retain the right to use it as an absolute last resort.
If there were an imminent threat to the world that could not be ended any other way, and I could be as confident as I possibly could be that there was no other way to do it, I may use it. I would feel that I had a moral duty to do so.
Using it as a tool of punishment and terror would be evil. Using it as a tool of retribution would be even more so. People should not have their lives extinguished, arbitrarily, without any opportunity for justice, based on their worst acts, by anyone.