Pakistan, Russia, the United Kingdom, the United States,[17] and France say they will use nuclear weapons against either nuclear or non-nuclear states only in the case of invasion or other attack against their territory or against one of their allies. Historically, NATO military strategy, taking into account the numerical superiority of Warsaw Pact conventional forces, assumed that the use of tactical nuclear weapons would have been required in defeating a Soviet invasion...The U.S. doctrine for the use of nuclear weapons was revised most recently in the Nuclear Posture Review, released April 6, 2010.[21] The 2010 Nuclear Posture review reduces the role of U.S. nuclear weapons, stating that
"The fundamental role of U.S. nuclear weapons, which will continue as long as nuclear weapons exist, is to deter nuclear attack on the United States, our allies, and partners."
The U.S. doctrine also includes the following assurance to other states:
"The United States will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the NPT and in compliance with their nuclear non-proliferation obligations."
For states eligible for this assurance, the United States would not use nuclear weapons in response to a chemical or biological attack, but states that those responsible for such an attack would be held accountable and would face the prospect of a devastating conventional military response. Even for states not eligible for this assurance, the United States would only consider the use of nuclear weapons in extreme circumstances to defend the vital interests of the United States or its allies and partners. The Nuclear Posture Review also notes that:
"It is in the U.S. interest and that of all other nations that the nearly 65-year record of nuclear non-use be extended forever."
This supersedes the doctrine of the Bush Administration set forth in "Doctrine for Joint Nuclear Operations" and written under the direction of Air Force General Richard B. Myers, chairman of the Joint Chiefs of Staff. The new doctrine envisions commanders requesting presidential approval to use nuclear weapons to preempt an attack by a nation or a terrorist group using weapons of mass destruction.[22] The draft also includes the option of using nuclear weapons to destroy known enemy stockpiles of nuclear, biological, or chemical weapons.[18]
At a NATO summit in April 1999, Germany proposed that NATO adopt a no-first-use policy, but the proposal was rejected.