Nuclear weapons policy is only a small part of a much bigger policy.
Nuclear weapons deter- this has been shown.
Nuclear weapons are efficient- this has been shown.
Better, more accurate nuclear weapons contain more deterance and efficiency. They are also safer to prevent unintended use. Tactical nuclear weapons can be used in situations where strategic weapons use would have the opposite effect.
Nuclear weapons must be maintained at the leading edge of technical advancement.
There are additional benefits of spin-off technology from research.
It is the bigger policy of how we relate to others in the world that needs changing.
On Edit: check out this one:
http://www.bullatomsci.org/I used to subscribe in the 80's but did not have the time to fully appreciate it.