French nuclear deterrence in Europe : does a diplomatic bomb threaten the NPT ? BonSens.org alerts IAEA

On March 4, 2025, a letter addressed to Rafael Mariano Grossi, Director General of the International Atomic Energy Agency (IAEA), shed a harsh light on an explosive proposal by French President Emmanuel Macron:  to extend France's nuclear deterrent to Europe. This letter form non-profit BonSens.org alerts to a possible violation of the Nuclear Non-Proliferation Treaty (NPT) and calls for an urgent investigation.

Non-profit @BonsensOrg has today sent an official registered letter (and by email) to Mr. Rafael Mariano Grossi, Director General of the International Atomic Energy Agency (@iaeaorg ), to report a possible violation of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT)…

— BonSens.Org (@BonsensOrg) March 4, 2025

While a France-Soir/BonSens poll in January 2025 revealed that 77% of French people consider the risk of nuclear war to be real, this initiative is divisive and worrying, reviving tensions around proliferation and global safety. What does this approach mean? Who is the IAEA? And why is this subject shaking the international order?

An alarming report

The request of BonSens.org is based on a clear premise: Macron's recent statements, relayed in particular by Le Parisien on March 3, 2025 (“Extend French nuclear deterrence to Europe”), could contravene Articles 1 to 3 of the NPT. This treaty, in force since 1970, prohibits nuclear-weapon states (such as France, with its 290 warheads – source statistica) from transferring these weapons or their control to non-nuclear-weapon states, and the latter from acquiring them. The idea of nuclear “sharing” with Europe or the European Union (EU) raises suspicions of indirect proliferation.

The letter points to a precedent: “nuclear sharing” within NATO, where countries such as Germany and Belgium host American weapons under strict US control. This arrangement, although controversial, is tolerated because Washington retains the final decision. On the other hand, if France went further - for example, by ceding operational control to the EU or to non-nuclear-weapon states such as Poland - it would be violating Article 1 of the NPT, exposing the treaty to a major crisis.

BonSens.org also insists on a legal point: neither Europe (a geographical concept) nor the EU (a supranational organisation) are signatory states to the NPT. Giving the EU nuclear power would imply either an illegal transfer of France, or a rupture by members who do not have their commitments. Adding a layer of defiance, the letter evokes the "mafia culture" within the European Commission, quoting mediator Emily O'Reilly in Politico (20 December 2024), to disqualify the EU as a potential nuclear weapons manager.

The request is clear: the IAEA must

• to investigate French intentions, to analyse official speeches,
• question stakeholders (France, Germany, Poland),
• and produce a technical report on compliance with the NPT.

In the event of a proven violation, the case could be referred to the UN Security Council.

What is the IAEA? A global nuclear sentinel

The IAEA, established in 1957 and based in Vienna, is an autonomous organization under the aegis of the UN. Its mandate, as defined by its Statute, combines  the promotion of peaceful nuclear energy with the prevention of military proliferation. With 175 member states by 2025, it plays a key role in verifying NPT commitments through its safeguards system—inspections and audits to ensure that nuclear materials are not diverted to weapons.

The IAEA is not a court, but a technical authority. It has gained global stature by investigating crises such as Iran's nuclear programme or securing threatened sites, such as Zaporizhzhia in Ukraine since 2022. In this case, it could ask France for clarification and assess whether the extension of deterrence remains doctrinal or crosses the red line of an operational transfer.

The context seems propitious but dangerous and contrary to the NPT - a bold France in an unstable world

Macron's initiative is part of a tense geopolitical climate. The Russia-Ukraine war, which began in 2022, has revived nuclear fears, with the IAEA itself warning of the risks around Ukrainian power plants. At the same time, the January 2025 France-Soir/BonSens poll shows growing anxiety: 77% of French people perceive a real risk of nuclear war, a figure reflecting the impact of East-West tensions and bellicose rhetoric.
 

Macron, often perceived as an opportunistic strategist who is not always well understood, is seeking to reposition France as a European leader. Since Brexit, it has been the EU's only nuclear state, and its arsenal—290 warheads deployed on submarines and Rafale aircraft—gives it a unique influence. Proposing a " European deterrent " could strengthen the EU's sovereignty in the face of Russia or China, while compensating for doubts about US involvement in NATO under Trump. But this audacity comes up against a legal and political wall.

The stakes: proliferation, safety, and mistrust

• Violation of the NPT? The letter of BonSens.org insists on the distinction between doctrine and action. If France extends its deterrence without transferring weapons or control, it remains within the limits, like the United States with NATO. But any ambiguity—for example, warheads deployed in Poland or a shared command with the EU—would be a rupture.
• Global nuclear safety : With 77% of French people fearing a nuclear war, and probably the same in other countries, the subject is explosive. A poorly controlled enlargement of the French umbrella could destabilize the strategic balance.
• Crisis of confidence in the EU : The letter criticises the supposed corruption of the European institutions, making the idea of nuclear control by the EU hardly credible.

Geopolitics in turmoil and the possible end of the NPT?

Never since the Cold War has the world seemed so close to a major geopolitical rupture, as evidenced by the idea put forward by Chrystia Freeland, candidate for the leadership of the Canadian Liberal Party, to rely on British nuclear weapons to protect Canada from Donald Trump's pressure (The Telegraph, March 3, 2025). This proposal, as bold as it is unprecedented, could mark a fatal turning point for the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), already weakened by decades of tensions and circumventions. If historically non-nuclear states like Canada consider sheltering under the arsenal of other powers, it risks leading to a cascade of proliferation, with each nation seeking to secure its sovereignty through similar means.

Added to this is a persistent rumor: tonight, in front of Congress,

Trump could announce the withdrawal of the United States from the UN, motivated by a desire to escape multilateral constraints in the face of an increasingly bellicose Europe.

This weekend, European leaders, such as Emmanuel Macron and Friedrich Merz, multiplied escalatory statements after the American decision to cut off funding to Ukraine, revealing a hawkish posture without the real means of their ambitions. Ursula von der Leyen has even proposed a European army with a colossal budget of 800 billion euros, an ambitious but uncertain response to an America that seems to be the only one to avoid a third world war.

In this context, an American withdrawal from the UN could be motivated by Trump's firm desire to prevent as quickly as possible the American ally from being lured against its will into a conflict that the Europeans do not seem to refuse with all their might. Indeed, the latter have given themselves the word to stir up the “perceived” risk of Russia's ambitions on other European territories. A risk that is much more theoretical than real, which therefore serves as a reason to try to rally Europeans to an escalation that is far from peace. If Trump were to take the United States out of NATO, it would lead to a rapid total reconfiguration of alliances

The NPT, Macron's declaration and a double betrayal in the making?

However, Chrystia Freeland's suggestion of the use of British nuclear weapons is also part of a climate in which French President Emmanuel Macron has opened the door to an extension of the French nuclear umbrella to Europe. This statement raises a troubling question : by proposing to share a nuclear arsenal with other European nations, does Macron not risk undermining the NPT from within, to the point of bordering on an act of betrayal of the founding principles of this treaty?

The NPT, which strictly limits the transfer of military nuclear technology, could be interpreted as violated if France formalized such a sharing with countries such as Germany, where Friedrich Merz has already called for joint access to French and British arsenals and the rebuilding of military power. Such a move, while motivated by fears of a US disengagement under Trump, could be seen as a provocation by other nuclear powers, led by Russia and China, accelerating an uncontrollable arms race.

But the betrayal does not stop at international borders. Within France itself, this proposal risks further fracturing a society already divided over the question of national sovereignty and strategic independence. By placing French nuclear weapons, the ultimate symbol of deterrence and Gaullist autonomy, at the service of a federal Europe, Macron could be accused of betraying a historical heritage dear to part of public opinion and military elites, who would see it as a dilution of French power in favor of an uncertain continental ambition.

If Macron is doing this to counter Trump's isolationism and respond to internal European pressures, he is playing a doubly dangerous game : compromising a pillar of global security while alienating part of his own nation. One more point to be taken into consideration in the assessment of the insane risks that President Macron is making the nation take. This leads to a reiteration of questions about the president's state of health. 

France-Soir and Macron's health: a president fit to handle the atom?

France-Soir had already expressed concern about Emmanuel Macron's ability to manage nuclear weapons. In 2024, faced with rumours about his health, the newspaper sought to locate Dr Perrochon, the president's personal doctor, to obtain clarification on his state of health – an obligation of transparency that President Macron had taken during his election campaigns, but which was not kept. Failing to get a clear answer, France-Soir referred the matter to the Constitutional Council, invoking Article 7 of the Constitution, which provides for the president to be prevented from doing so in the event of incapacity. Their question was brutal:  does Macron have the physical and mental conditions to control an arsenal of 290 nuclear warheads?

This approach, although mediatic, raises a legitimate question. The French president has almost absolute power over deterrence, being able to order a strike without mandatory consultation. If his health or lucidity were to be impaired, as some fear in the face of his diplomatic-military activism, the implications would be serious, especially with a proposal as risky as European nuclear sharing. The Constitutional Council has not followed up publicly, but the episode fuels doubts about the stability of the decision-maker behind this initiative.

Possible reactions and scenarios

The IAEA could accept the request for an investigation, launching an analysis of Macron's speeches and questioning Paris about his intentions. If France clarifies that its deterrent remains under national control, the matter could die out. But a refusal or evidence of operational sharing would lead to a damning report.

An investigation to defuse the crisis?

The letter to Grossi, amplified by France-Soir's concerns about Macron, crystallizes the anxieties of an era. The extension of French deterrence, if it remains theoretical, is a bold move. But if it becomes reality, it could crack the NPT and confirm the fears of the 77% of French people surveyed. The IAEA must investigate carefully, while the president's health adds a layer of uncertainty. Grossi's answer will tell whether this diplomatic bomb goes out or explodes.

The legitimacy of the BonSens.org association: an interest in taking action?

BonSens.org is a French association founded in 2020 and has become known for its critical stance on public policies, particularly on transparency and health. Its legitimacy to refer the matter to the IAEA is based on its status as a civil society actor concerned with public safety and global governance. Although the IAEA does not deal directly with NGOs, BonSens has an interest in taking action: alerting to the risk of nuclear proliferation affects its mission of defending the health of citizens in the face of decisions perceived as opaque or dangerous. However, its influence remains limited vis-à-vis states, and its approach could be seen as symbolic, aimed at amplifying public debate rather than obtaining a direct institutional response.