Sheer stupidity. Not to mention complete hypocrisy.
And besides, as a signatory to the Nuclear Non-Proliferation Treaty, isn't America (and the other four "legal" nuclear powers) obliged to work towards nuclear disarmament? How does building new nuclear warheads contribute to disarmament? How does building new nuclear warheads build trust around the world? How does this contribute to peace or America's national security?
Like I said, this is sheer stupidity.