In the United States, the President has sole authority to authorize the use of nuclear weapons. This authority derives from the President’s constitutional role as Commander-in-Chief and has been longstanding policy (reaffirmed in documents such as the Department of Defense/War nuclear employment strategy reports). Neither Congress, the Secretary of Defense/War, the Chairman of the Joint Chiefs of Staff, nor other military officials must concur, and they cannot overrule a lawful presidential order. Operational Chain of Command Federal law (Title 10 of the U.S. Code) establishes the military chain of command as running: • From the President • To the Secretary of Defense/War • Directly to the commanders of the unified combatant commands (for strategic nuclear forces, primarily the Commander of U.S. Strategic Command, or STRATCOM). The Chairman of the Joint Chiefs of Staff is not in the chain of command and exercises no military command over combatant forces. The Chairman serves as the principal military advisor and participates in the “chain of communication” (relaying information, advising, and helping authenticate/process orders in a decision conference). How a Launch Order Works (Nuclear Command, Control, and Communications / NC3) 1. Decision and consultation: In a crisis (or for planned employment), the President typically receives briefings and confers with advisors (Secretary of Defense/War, military leaders including STRATCOM, and others) on options, implications (military, legal under the law of armed conflict, diplomatic, etc.), and risks. Consultation is expected and facilitated by secure systems, but it is not legally required for the President to decide. 2. Authorization tools: The President uses the “nuclear football” (a briefcase carried by a military aide containing communications gear, options/codebooks, and related materials) and authenticates identity with codes from a card known as the “biscuit” (Gold Codes). 3. Transmission: Once authenticated (often via a challenge-response with the National Military Command Center/NMCC at the Pentagon), the order is formatted as an Emergency Action Message (EAM) specifying the selected option. It is transmitted through secure channels to STRATCOM (and relevant commands), which relays it to the forces: ICBM launch crews, ballistic missile submarine commanders, and strategic bomber crews. 4. Execution: Launch crews perform their own verification and execute. No single person can both authorize and physically launch; the system separates presidential authorization from the technical enablement at the weapons/crews. The system is designed to be assured, timely, secure, survivable, and enduring so the President can direct forces even under attack, while preventing unauthorized or accidental use. The Secretary of Defense/War’s practical role is typically to help verify that the order originated from the President and to assist in transmission—not to approve or veto the decision itself. ⚠️WARNING⚠️ There is no mechanical (technical or procedural) distinction in the U.S. nuclear command, control, and communications (NC3) system between an order for first use of nuclear weapons and an order for a retaliatory strike. The authentication, transmission, and execution processes are the same regardless of the scenario. What This Means in Practice The system is built around a single pathway for presidential authorization: • The President authenticates identity (via codes from the “biscuit” and the nuclear football). • An Emergency Action Message (EAM) is formatted with the selected option from available war plans. • The message is transmitted through the National Military Command Center (or equivalent secure channels) to U.S. Strategic Command and then to the relevant forces (ICBM crews, submarine commanders, bomber crews). • Those forces verify the order and execute. None of these steps includes a technical filter, different code set, alternate channel, or hardware interlock that activates only for retaliation (e.g., after confirmed incoming missiles) versus first use (initiating nuclear employment without a prior nuclear attack on the U.S. or its allies). The same unlock/arming codes and procedures apply. The system prioritizes reliable execution of any lawful presidential order under tight time constraints while preventing unauthorized use. Pre-planned options in the presidential decision materials (sometimes called the “Black Book”) cover a spectrum of scenarios — major attack options, limited/selected options — but the mechanism for selecting and transmitting one does not change based on whether it is framed as first use or response. Furthermore, the United States has never adopted a “no first use” policy. Official guidance maintains calculated ambiguity — the President retains the option to use nuclear weapons first in extreme circumstances to defend vital interests. Military leaders may advise on compliance with the law of armed conflict (necessity, distinction, proportionality), but this is advisory. congress.gov