This is something that we should be doing too. Sarkosy has announced that the French nuclear arsenal will be cut to less than 300, about half of what it was at its peak.
This is a good step for everyone. Currently, according to the wiki, “[the USA] maintains a current arsenal of around 9,960 intact warheads, of which 5,735 are considered active or operational”.
I see no reason that we could not drop down to below 1000 operational warheads.