

and allied nuclear forces, nuclear command and control systems, or warning and attack assessment capabilities. While reiterating that the United States would use nuclear weapons only in extreme circumstances, the review said that those circumstances included “significant non-nuclear strategic attacks” on U.S., allied and partner civilian populations, U.S. Instead of reducing the role of nuclear weapons and rejecting new nuclear weapons, the 2018 review called for new “supplemental” nuclear capabilities: a low-yield submarine-launched ballistic missile warhead and low-yield warhead for a sea-launched cruise missile. The Trump administration’s 2018 nuclear posture review reflected continuity with its predecessor in some ways but diverged in others. The review added that the United States would “continue to strengthen its conventional capabilities and reduce the role of nuclear weapons in deterring non-nuclear attacks” with the goal of making deterring nuclear attacks the sole purpose of the U.S. That language left open the possibility of a nuclear response to a conventional attack by a nuclear weapons state or another country not covered by the negative security assurance. nuclear arms was to deter a nuclear attack on America, its allies or its partners. The 2010 nuclear posture review also stated that the United States would resort to nuclear weapons only in extreme circumstances and that the “fundamental purpose” of U.S. As reported by Fred Kaplan in The Bomb, in 2017, Secretary of Defense Jim Mattis asked a group of senior Pentagon officials if they believed that nuclear war could be controlled only one thought that it was possible. That might have contributed to the deterrence of a conventional conflict, but such escalation would have entailed enormous risks: once the nuclear threshold was crossed, where would matters stop? Many analysts question the ability to control escalation once nuclear weapons enter into use. and NATO officials maintained an explicit option for deliberate escalation to nuclear weapons in the event of a conflict where they were losing at the conventional level.

When the Soviet Union and Warsaw Pact held large numerical advantages in conventional military forces during the Cold War, U.S. Indeed, it explicitly preserves that possibility.

That formulation leaves ambiguity as to whether an American president might in some cases decide to use nuclear weapons first. government has long taken the position that it would use nuclear weapons only in “extreme circumstances” in which the vital interests of the United States, its allies or partners were at stake.
