Our current stockpile is only at ~4700 nuclear warheads. Mind you that over half of those warheads are MIRV on the Minuteman III ICBM and the Trident II SLBM. Minuteman III carries 3 warheads. Trident II carries 8 warheads, there are 24 Trident II missiles on a ballistic missile sub. A single ballistic missile sub carries 192 warheads. We have 14 SSBNs. Our sub fleet alone carries 2688 warheads. Our stockpile should be considerably larger. It is also cheaper to develop new warheads than to maintain older models.
Isn't there some sort of moratorium of developing new? Or is it just a moratorium on testing? Agree with you, cost of new (and reliability of new) favors shifting to new.
Thanks for the corrections on size of stockpile. My general point was that the issue is probably more complex than what Trump has in his head right now. The size of the stockpile is a strategic calculation, and tough of its own right.