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No First Use policy is just common sense, and former military officials including former Secretary of Defense William Perry agree. But we know there are a lot of questions about how it would work. We recommend first learning more about No First Use from our main No First Use page before reading the FAQs below. These answer some of the most common in-depth questions our experts receive. You can also check out our myths vs. realities guide for rebuttals to common misconceptions.


Under current U.S. policy, when can the president order a nuclear strike?

Current U.S. policy does not restrict the president’s ability to order a nuclear strike for any reason at any time. The military may reject an order that is perceived to violate laws of war, and there are legal concerns about the role of Congress authorizing the use of force, but as a matter of broad understanding, the president can launch nuclear weapons when and if s/he chose to.


In the context of U.S. nuclear policy, what is the difference between “No First Use,” “sole authority” and “sole purpose?”

  • A “No First Use” (NFU) policy is a commitment to not use nuclear weapons first. An NFU policy would restrict when a president could consider using nuclear weapons, and would help signal that the United States believes that nuclear weapons are for deterrence—not warfighting.
  • Sole authority refers to the current U.S. nuclear posture in which the President alone can order the launch of nuclear weapons at any time for any reason without checks from the other branches of government. While a president may (and most likely would) consult with their national security team before ordering a nuclear attack, s/he is not required to seek advice or agreement from anyone. Proposals to eliminate sole authority address the question of who would authorize a nuclear strike. Eliminating sole authority would require changing launch procedures to require consent from other individuals in government to conduct a nuclear attack in any scenario, not only a nuclear first strike.
  • “Sole purpose” refers to a commitment only to use nuclear weapons to deter nuclear attacks. This means that U.S. nuclear forces would not be used to deter conventional, chemical, biological, or cyber attacks. Current policy as set out in this Administration’s Nuclear Posture Review would allow the United States to use nuclear weapons in “…extreme circumstances to defend the United States, its allies, and partners.” Declaring sole purpose would clarify what nuclear weapons are for.


Are there any cases in which the United States needs to use nuclear weapons first?

The United States’ conventional force is robust and capable, and Washington does not need to resort to using nuclear weapons first. In fact, being the first to use a nuclear weapon would be exceptionally risky. The chance that a nuclear first strike by the United States would escalate to an all-out nuclear war is unacceptably high. A nuclear exchange could threaten the security of U.S. allies, and being the first to use such a destructive weapon could leave the United States politically isolated.


What if the president orders a nuclear attack illegally?

A military order must meet certain requirements under the Laws of Armed Conflict. If it is not militarily necessary to destroy a particular target; the attack will cause unnecessary human suffering; the military advantage does not outweigh the human cost; or combatants and non-combatants have not been distinguished, an order would be illegal. Individuals in the chain of command may refuse to follow orders that they believe to be illegal. However, the Congressional Research Service notes that objections would be “…more likely to result in consultations and changes in the president’s order than a refusal by the military to execute the order” in a case where the use of nuclear weapons has been ordered.


How would a No First Use policy change the president’s ability to use nuclear weapons?

The United States could adopt an NFU policy by enacting legislation or a president could issue an executive order. Different formulations of a No First Use policy would modify a president’s power to use nuclear weapons in different ways. The No First Use Act (HR 921/S 272-Smith/Warren) would modify U.S. declaratory policy to state that the United States would never use nuclear weapons first. The Restricting First Use of Nuclear Weapons (HR 669/S 200-Lieu/Markey) would require a president to get approval from Congress to use nuclear weapons first through an authorization for the use of military force. In any of these cases, if an adversary attacked the United States or its allies with nuclear weapons, the president could respond with a nuclear attack.


What are the benefits of a No First Use policy?

Adopting an NFU policy would enhance U.S. and allied security by minimizing ambiguity about how the United States thinks about and intends to use its nuclear weapons. Clarifying that the U.S. nuclear arsenal is only for deterrence would reduce the risk of adversaries miscalculating U.S. intentions and unintentionally escalating a crisis.

Using nuclear weapons first is tantamount to a declaration of war, a responsibility that lies solely with the U.S. Congress. Adopting an NFU policy would reaffirm Congress’s constitutional authority to declare war. The Constitution makes clear that no president can start a war by his/herself, so it makes sense that a president should not be able to start a nuclear war alone.

On the international stage, adopting an NFU policy will demonstrate that the United States is reducing the role of nuclear weapons in its strategy and policy at a time when non-nuclear weapons states are increasingly frustrated that nuclear-armed states are not making satisfactory progress on their commitments to work toward disarmament under Article VI of the Non-Proliferation Treaty.