Three minutes, a football and a biscuit. These are all a president of the United States needs to start nuclear war. During a 1974 meeting with lawmakers, Richard Nixon reportedly stated: “I can go into my office and pick up the telephone, and in 25 minutes 70 million people will be dead.” He was correct. And since then, despite the end of the Cold War and collapse of the Soviet Union, little has changed.

The nuclear launch process and the law that gives the President such power, enhanced by 21st-century technology, combine to form a perfect storm in which the commander-in-chief can choose to launch nuclear weapons via an unforgiving process that leaves little to no room for mistakes.

In the United States, the President is the only person in the country who can legally order the use of nuclear weapons, a power referred to as “sole authority”. The President may choose to consult with advisers but is not required to do so. He can order nuclear use despite the objections of every adviser in the room.

Naturally, the President should want to consult with his top advisers. But with norms collapsing across all facets of government — even national security — enhanced guardrails are called for. Nuclear use should not depend on the whims of one person.

Presidential sole authority was established at the beginning of the nuclear age during the Truman Administration owing to Harry Truman’s desire to keep nuclear weapons out of the hands of overzealous, trigger-happy generals — “some dashing lieutenant-colonel”, as he put it. A formal policy was established in 1948, declaring: “The decision as to the employment of atomic weapons in the event of war is to be made by the Chief Executive when he considers such a decision to be required.” The policy remained in place throughout the Cold War — and is upheld to this day.

Anyone who looks closely at images of US presidents out and about — on their way to or from a meeting, boarding Air Force One or even out for a run — will notice a constant presence trailing behind the President: a military official carrying a large, black briefcase. The approximately 40-pound leather satchel is known as the “nuclear football”, and it allows the President to order the launch of nuclear weapons at any time from any location.

Contained within the nuclear football is everything the President needs to make the order. Contrary to many pop-culture references, this does not include a big red button. It does, however, include the “black book”, which lists a president’s options for the timing, type of delivery system and targets for a nuclear strike. The black book used to comprise a heavy set of war plans, but after Jimmy Carter complained that its contents were too dense and complicated, it was simplified into a sort of menu of attacks for the President to choose from. The start of nuclear war, the probable deaths of millions and the choice of which cities to decimate — the black book distils these realities into a sanitised list of options that a former military aide to Bill Clinton likened to a “Denny’s breakfast menu”.

Accompanying the strike menu is secure communications equipment that allows the President to call the Pentagon’s National Military Command Centre to relay the order. To verify a launch order, the President must identify himself with a unique code. The code is inscribed on a small card known as the “biscuit”, which the President carries on his person at all times. Once the President’s identity is confirmed and the order is transmitted, the Pentagon could execute the launch order in about one minute. If the President chose a strike option that included intercontinental ballistic missiles, the missiles would fire in approximately two minutes. There is no way to recall or disarm ICBMs once they have launched.

Experts estimate that — to ensure the ability of the United States to retaliate before an incoming attack lands and potentially takes out the command and control system, or the President himself — a president would have less than ten minutes to process the situation and review his options before having to make a decision on whether to launch nuclear weapons.

The rationale behind this process is that it allows a president to respond rapidly and decisively in the case of an imminent nuclear attack headed towards the United States. During the Cold War, this was seen as the best — and perhaps the only — way to deter a bolt-from-the-blue nuclear attack from the Soviet Union, convincing Soviet leadership that the US president would be able to respond in kind before their attack landed.

When the Soviet Union dissolved and the Cold War ended, the threat of a massive surprise attack dissipated. Yet the system that emphasised speed in launching nuclear weapons remained in place.

Some national security officials argue this process is still necessary. But the President’s authority to order nuclear use is not limited to cases of imminent or confirmed attack on the United States. The President can, legally and logistically, simply command the Pentagon to launch.

False alarm

Even when warning systems indicate an attack is under way, it might be a false alarm. That has happened on several occasions in the past, as recently as 2018.

On the morning of January 13, 2018 — just days after Donald Trump and North Korea’s Supreme Leader, Kim Jong Un, lobbed nuclear threats at each other — smartphones across Hawaii received an alert from the state’s Emergency Management Agency: “Ballistic missile threat inbound to Hawaii. Seek immediate shelter. This is not a drill.”

But the attack didn’t come. Someone at the EMA had pushed the wrong button. If a false alert of multiple incoming nuclear missiles had happened within the national warning system, the President would have been alerted and could have initiated a nuclear launch before it was discovered to be a false alarm.

One of the most dangerous publicly known false alarms occurred on November 9, 1979. Warning screens at the Pentagon’s NMCC and three other command centres suddenly lit up, showing nearly 1,500 Soviet ballistic missiles headed towards the United States. Per proper procedures, fighter jets were put to the sky, nuclear bomber crews were ordered to their aircraft, nuclear missile crews were put on high alert and the President’s emergency airborne command post, known as the “doomsday plane”, took off. Six minutes after the alert began, officers at the North American Aerospace Defence Command discovered that a training cassette simulating a Soviet attack had mistakenly been entered into their primary computer system and broadcast to other command centres.

Numerous incidents such as these throughout the nuclear age have revealed the susceptibility of early warning systems to human and technical errors. Today, cyberthreats pose an additional concern and exacerbate the vulnerability of these systems. Such vulnerabilities, combined with the speed with which a president can react, heighten the risk of a US president starting a nuclear war by mistake.

Avoiding nuclear disaster also depends on the rationality and stability of whoever occupies the Oval Office. Two presidents of the nuclear age — Nixon and Trump — displayed erratic behaviour that led high-ranking officials to attempt to insert themselves into the nuclear chain of command as a safeguard against the presidents’ power. However, neither Defence Secretary James Schlesinger in 1974 nor Chairman of the Joint Chiefs of Staff General Mark A. Milley in 2020 had the legal authority to do so. Subordinates at the NMCC or missile launch facilities would not have been obligated to follow their orders.

The US Uniform Code of Military Justice — the foundation of the US military justice system — makes disobeying legal orders from a superior during peacetime punishable by dishonourable discharge, forfeiture of pay or even a five-year confinement. During wartime, disobeying legal orders can be punishable by death. The UCMJ also obligates military members to disobey illegal orders. This puts young service members in the position of having to make split-second legal determinations as non-legal-experts while under intense stress and likely without knowing why the order was issued. Additionally, there is a presumption that orders from a superior officer — and, particularly, those given by the commander-in-chief — are legal. We cannot rely in perpetuity on one person’s willingness to step forward to protect against the whims of an irrational or unstable president.

Several proposals have been put forward to prevent a president from being able to use nuclear weapons in contravention of the national interest. A central challenge, however, is that experts disagree on the primary problem with the existing system. Is it unconstitutional for a president to unilaterally launch nuclear weapons, thereby starting a war, which is a power reserved for Congress? Does sole authority bias a president in favour of nuclear use? Does it place an unfair burden on military subordinates who have to carry out a catastrophic order? Or is the real problem that ICBMs can launch within two minutes, leaving too little time for correction?

But almost all experts agree that something needs to change. In 2021, nearly 700 scientists and other experts signed a letter asking Joe Biden, among other nuclear risk-reduction measures, to alter the policy of sole authority to safeguard against a “reckless” or “unstable” future president. As the world enters a new age of heightened nuclear risk with expanding global nuclear arsenals, increased prevalence of nuclear threats and aggressive rhetoric, shortening decision time and cyber capabilities, diminishing diplomacy and transparency, and a US president with a history of making nuclear threats, action is urgently needed to reduce the risk of nuclear war.

• Mackenzie Knight-Boyle is a senior research associate for the Nuclear Information Project at the Federation of American Scientists