[dzptgvlz] Governments which responsibly use nuclear weapons

Objectively, a government should be permitted to have nuclear weapons only if they will use (and store) them "responsibly", a concept yet to be precisely defined, perhaps not causing extinction of the human race.

Define some criteria that governments should meet to be permitted to have nuclear weapons.  Which of the current nuclear powers satisfy these criteria?  Which countries seeking nuclear weapons satisfy these criteria?

One criterion should probably be something about, when there is a transition of power in a government, the successors will continue to be responsible stewards of their inherited nuclear arsenal.  This criterion seems impossible to meet.