The new nuclear capabilities now being considered by the United States include powerful earth penetrating nuclear warheads intended to destroy underground facilities, "agent defeat" weapons to destroy chemical and biological weapons and support facilities while limiting damage from both release of hazardous materials and the nuclear explosion itself, and new variants of relatively "low-yield" nuclear weapons intended to make nuclear weapons more useable in ordinary warfare. These types of nuclear weapons, however, are likely to be "small" only in comparison to the city-busting bombs and warheads that make up most of the current active nuclear stockpile, and would be likely to cause widespread death and long lasting environmental damage if used. In the context of an aggressive U.S. policy that envisions preventive wars against countries that are even suspected of having or seeking to acquire chemical, biological, or nuclear weapons, the push for new kinds of nuclear weapons, even more than the continued possession of substantial parts of the Cold War arsenal, legitimates nuclear weapons as an instrument of state power, and provides arguments for their acquisition by other states.

These policies are inconsistent with U.S. obligations under the Nuclear Non-Proliferation Treaty (NPT), in which the U.S. and the other four original nuclear powers agreed to negotiate in good faith towards the elimination of their nuclear arsenals. This obligation was reaffirmed at the NPT review conference in 2000, at which the United States and the other original nuclear powers agreed to a new set of commitments to take concrete steps towards nuclear disarmament. These commitments included an unequivocal undertaking to accomplish the total elimination of their nuclear arsenals; the principle of irreversibility as applied to nuclear disarmament and related arms control and reduction measures; concrete measures to reduce the operational status of nuclear weapons; and a diminishing role for nuclear weapons in security policies. Despite these commitments, the U.S. is researching new missions and capabilities for nuclear weapons. And despite its commitment to "the principle of irreversibility to apply to nuclear disarmament," the United States today is proposing to build the Modern Pit Facility, a factory that will allow it to mass produce the core component of nuclear weapons into the second half of the 21st century.