Nuclear Weapons Part IV – A Postscript

Editors’ note: This is the fourth of a four-part post on legal considerations applicable to nuclear weapons.

The first three posts in this series were completed on February 26, 2026, approximately 48 hours before the outbreak of the most recent period of hostilities involving the United States, Israel and Iran. Much has, and will increasingly in the future, be written about the ensuing period of armed conflict. It is not the purpose of this post to discuss what has come to be known as the Iran War as such.

Neither will this post focus on the continuing armed conflict between the Russian Federation and Ukraine, although as shown below that war does have some significance where nuclear disarmament prospects are concerned. What this brief postscript does seek to address is whether those two wars have implications for nuclear disarmament.

The Nuclear Implications

In the third post in this series, the author was seeking to suggest realistic ways of achieving reduced tensions, a reduction and eventual cessation of the nuclear arms race and, ultimately, progress towards nuclear disarmament in conformity with the obligations in Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and as referred to in the International Court of Justice (ICJ)’s findings in its Nuclear Weapons advisory opinion. In that series of posts, mention was made that during the last 80 years there has been an absence of direct hostilities between nuclear-armed States and that is an assertion that is not affected by the current hostilities. Iran was not, on February 28, 2026, a nuclear-armed State. The military operations against Iran in June 2025 had, reportedly, done much to damage facilities associated with Iran’s nuclear programme, and the hostilities since that date have, again reportedly, included the targeting of such facilities and installations. Put simply, U.S. and Israeli operations in this regard are aimed at ensuring that the number of nuclear-armed States remains at nine and that Iran does not achieve that capability.

A second key implication of both wars, Russia v. Ukraine and the Iran War, is that numerous States will now be reevaluating their security situations and plans. Indeed, it is significant that France has announced it will be increasing its nuclear arsenal as a direct response to recent events and that it will be extending nuclear umbrella arrangements to its European allies. There is, however, a powerful argument that it is illusory to seek enhanced security through possession of, or umbrella status with regard to, nuclear weapons. The argument is that security based on possession of a capability that risks destroying humanity in general is no security at all. Perhaps what matters is the view that a significant number of States actually take, namely that having nuclear cover, whether by possession or an umbrella arrangement, is more likely to secure the State against attack than not having such cover.

It is this perceived link, rational or otherwise, between nuclear deterrence and feelings of enhanced security that is the vital factor. Some observers will then reflect on the Ukrainian experience. Ukraine, which at the time held the world’s third largest nuclear arsenal, agreed to return all of its nuclear warheads to Russia, a process completed in 1996. It did this in exchange for security guarantees from the United States, the United Kingdom and Russia; two of these, arguably, did not succeed in providing the relevant security and the third has actually attacked Ukraine and continues to do so. One can debate the circumstances that caused Ukraine to surrender the relevant weapons, but the point that many will draw from this is that by becoming a non-nuclear weapon State, Ukraine to a greater or lesser extent opened itself up to the attacks of 2014 and 2022, and thereafter. Certainly, there will be those who conclude that Russia would have been much more hesitant about invading a nuclear-armed Ukraine.

It is, perhaps, worth noting the links between the two conflicts. Russia has been a supporter of Iran for many years but noticeably has refrained from overtly coming to its aid. Similarly, United States support for Ukraine has been carefully calibrated. Both major powers have been astute in not overstepping an invisible, but seemingly mutually understood line. The clear purpose of both is to avoid direct armed conflict between them, what one might see as nuclear deterrence at work.

It remains to be seen how both armed conflicts will progress. In this current unstable global environment, the prospects for nuclear disarmament seem bleak. Indeed, one cannot escape the thought that while the NPT Article VI obligations remain as a matter of treaty law, they are likely to receive a stiff ignoring from nuclear-armed States, at least for the time being. So the global instability that we are witnessing suggests that nuclear and general disarmament are “taking a back seat.” The States that have nuclear weapons are likely to maintain, or even uprate, their arsenals and the regime set forth in the UN Charter in which States abstain from the non-defensive, non-collectively authorised use of force is undergoing a degree of strain that risks breaking it altogether.

Conclusion

Perhaps what is now needed as a pre-cursor to the measures somewhat optimistically proposed in the third post in this series is a collective re-commitment by all States, including the most militarily powerful, to the core values written in the immediate aftermath of the bloody events of 1939 to 1945. Key principles need to be repeated, committed to by all States, and complied with. These include the prohibition of aggressive war, the prohibition of the use of non-defensive, non-collectively authorised force, the prohibition of the use of surrogates to perform similar activities, and other principles designed to promote international peace and security.

It is perhaps not excessively naïve to suggest that it is only by replacing contemporary hatreds and vengeance with mutual respect and peaceful cooperation among States that there can be any hope of lasting peace. “Blessed be the peacemaker” was, it is suggested, never more true, but to be a peacemaker involves understanding the core issues that divide us and finding a way in which to avoid threats, violence, provocation, and the many other activities that turn international relations towards warfare.

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Air Commodore William H. Boothby retired as Deputy Director of Royal Air Force Legal Services in July 2011. He is Honorary Professor at the Australian National University and also teaches at the University of Southern Denmark and at the Geneva Centre for Security Policy.

The views expressed are those of the author, and do not necessarily reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.

Articles of War is a forum for professionals to share opinions and cultivate ideas. Articles of War does not screen articles to fit a particular editorial agenda, nor endorse or advocate material that is published. Authorship does not indicate affiliation with Articles of War, the Lieber Institute, or the United States Military Academy West Point.

Photo credit: Yves Alarie via Unsplash