General John Hyten is the Commander of US Strategic Command (USSTRATCOM). USSTRATCOM is responsible for the entire arsenal of US nuclear weapons currently deployed on Minuteman missiles, Trident submarines and on B-2 and B-52 bombers.
General Hyten stated, at a conference in Nova Scotia on Saturday, November 18th, 2017, that if he considered a nuclear ‘launch’ order by President Trump to be illegal, he could refuse the carry out the order.
“We’re not stupid,” he said. “If you execute an unlawful order, you will go to jail. You could go to jail for the rest of your life…”
But what does General Hyten consider to be an ‘illegal’ or ‘unlawful’ order? And when it comes to launching nuclear weapons, under what circumstances might that be considered ‘legal’?
If General Hyten were to go to jail for executing an unlawful order, it would not be the laws of the federal government or the international laws of war that would put him there. Instead it would be the US military laws as defined and described in the Department of Defense Law of War Manual.
The Law of War Manual (LOWM) covers two broad areas of law relating to war: the first relates to the circumstances under which war is allowed in the first place (jus ad bellum), while the second relates to the conduct of war once it has started (jus in bello).
Under US military law, the use of military force against another nation is considered legal in only three circumstances: 1) if authorized by the United Nations Security Council, (2) if justified as a case of ‘self-defense’, or (3) if ‘invited’ by the country concerned (LOWM, 1.11.3, pp 43ff).
The US military’s definition of ‘self-defense’ is very broad, and includes the right to attack another country if there is a ‘reasonable belief’ that the US is under an imminent threat of attack.
So-called ‘preventive self-defense’, however, which is aimed at knocking out a threat to the United States that is considered real but not necessarily ‘imminent’, is illegal under US military law (LOWM, 1.11.5, pp 46ff).
We therefore have the first clear guidance as to what might be considered an illegal order to launch nuclear weapons under US military law: it would not be legal to launch a nuclear attack on any other country unless there was a reasonable belief that an actual attack on the United States was not just ‘real’ but ‘imminent’.
The two fundamental principles governing the conduct of warfare are ‘distinction’ and ‘proportionality’. These require all military operations to be conducted so as to minimize the likely effects on civilians. That means, in the first instance, that civilians or civilian structures can never be the target of an attack (LOWM, 2.5.2, p63).
Thus we have the second clear case of a nuclear launch order that would be illegal: ordering the launch of nuclear weapons targeted at cities or civilian infrastructure in any other country.
Even if military facilities and not cities are the ‘target’, it is impossible to imagine the use of weapons many times more powerful than the bomb which destroyed the entire city of Hiroshima as being in any way ‘proportional’ to any military advantage gained or able to make a ‘distinction’ between the civilian and military casualties that would result.
In addressing this issue, the Law of War Manual quotes the World Court advisory opinion of 1996, which stated that the use of nuclear weapons might be legal under certain circumstances (LOWM, 6.18, pp 416ff).
The circumstances considered by the World Court referred to the use of a very low yield nuclear weapon (ie. less than 1 Kiloton) against ships on the open sea or on a battlefield far away from civilian areas, where the radiation would not spread to civilian population centers or lead to lingering, long-term suffering even of the soldiers being attacked.
The irony is that such a scenario, still possible to envisage in 1996, was no longer plausible soon thereafter. Why? Because all the ‘very low yield’ nuclear weapons were removed from service.
The smallest nuclear weapon regularly deployed by the United States (100 Kilotons) is already more than six times as powerful as the bomb dropped on Hiroshima (15 Kilotons). The largest nuclear weapons routinely carried on US Trident submarines are, at 475 Kilotons, more than thirty times as powerful as the bomb dropped on Hiroshima.
It was announced in January 2020 that the new W-76-2 nuclear warhead was now operational on some US Trident submarines. This new “low-yield” warhead has an estimated yield of 5 Kilotons, roughly one-third the size of the Hiroshima bomb. That still makes it more than 250 times more powerful than the largest conventional bomb in the US arsenal, and with significant potential for widespread release of radioactive fallout.
Launching any of the nuclear weapons currently in the US arsenal, therefore, even against strictly military targets, would therefore almost certainly result in widespread carnage of civilians as well as radioactive fallout affecting a much wider area.
Unless such an attack could be justified as ‘proportional’ to the military advantage gained while still maintaining the fundamental distinction between combatants and non-combatants, it would, again, be an illegal launch order.
Also quoted in the Law of War Manual is the World Court opinion of 1996 that ‘there exists no general prohibition to the use or threat of use of nuclear weapons’ (op cit). This is quoted as evidence that the use of nuclear weapons as such ‘are not prohibited by international law’.
This is out of date, however, because a general prohibition to the use or threat of use of nuclear weapons does now exist – enshrined in the new Treaty on the Prohibition of Nuclear Weapons, which entered into force on January 22, 2021, after being ratified by 50 countries.
The United States has not signed this treaty and does not consider itself bound by it. Nevertheless, were the World Court to be asked today for its opinion on the legality of nuclear weapons, it would have to cite the fact that there does now exist in international law a general prohibition against any use of nuclear weapons, accepted by a majority of states and which will eventually enter into the realm of ‘customary international law’ that applies, legally, even to those states who do not sign it.
The Department of Defense Law of War Manual makes clear that, in general, the US military are bound, not only by what is considered to be customary international law, but also by “modern international public opinion as to how military operations should be conducted…even if that rule does not apply to U.S. forces as a matter of law”(LOWM, p. 71). That would make any nuclear launch order by the President an illegal order.
Timmon Wallis, PhD,
author, Disarming the Nuclear Argument, Luath Press, 2017.