A new window into France’s nuclear history
Access to French nuclear archives has increased dramatically during the past year. Since October 2021, French officials have declassified thousands of documents about the development of French nuclear weapons, an arsenal of roughly 300 warheads today.
This work marks a sea change in France, for decades one of the most difficult nuclear-armed democracies to study. Unlike the United States and the United Kingdom, France does not have Freedom of Information laws, which allow the public to file declassification requests. French archives do consider special access requests (dérogations), but these requests cannot compel a declassification review, which limits their utility in making nuclear weapons documents available for research.
French President Emmanuel Macron, in the wake of prize-nominated journalism and scholarship on the development of French nuclear weapons, launched a significant declassification initiative last year. This process has focused on Polynesia, the semi-autonomous French territory where French forces conducted nearly 200 atmospheric and underground explosions from 1966 to 1996. The scope does not include Algeria, the former French colony where French authorities built and operated their first nuclear test sites between 1960 and 1966, during the Algerian War for Independence (1954–62) and the construction of the postcolonial Algerian state.
New French transparency could help settle debates about environmental contamination and health effects from radiation exposure, especially in Polynesia. French law has promised to compensate victims of French nuclear weapons development who become sick or die from radiation-linked illness but has made only slow progress since 2010. Other nuclear-armed democracies, including the United States and the United Kingdom, have established similar compensation programs.
In France, newly available documents could answer strategic questions about French nuclear capabilities during the Cold War, political questions about official responsibility arising from the enigmatic French decision process, and social questions about interactions between French and Polynesian groups and individuals. Macron’s declassification initiative could also change perceptions of a tense relationship between nuclear secrecy and French democracy. Yet crucial gaps remain in access to French nuclear archives, especially records from the earliest years of the weapons testing program—when it took place in Algeria—and records concerning foreign affairs.
Ensuring nonproliferation. Since 2008, French law has indefinitely withheld “information allowing for design, fabrication, usage, or locating of nuclear weapons.” French officials say this restriction aims to prevent nuclear proliferation, but French archivists tend to interpret the ban broadly. The practical impact of the 2008 law exceeds its narrow-sounding language.
One French archivist explained to me that, not having nonproliferation training, archivists tend to interpret the 2008 law broadly out of humility and caution. They hesitate to determine which information the 2008 law withholds and to distinguish this restricted information from other information pertaining to nuclear weapons. Another French archivist told me that they learn to approach collections in terms of boxes, or perhaps folders, rather than individual documents. A few pages potentially jeopardizing nonproliferation policy can block access to an entire box.
Although the 2008 law has not changed, recent French declassification work has treated the nonproliferation restriction more narrowly. One French archivist told me that the declassification team assembled by Macron deliberately changed their approach, and it appears to have worked. This new approach delegates the nonproliferation determination to French nuclear planners, a change that has broken the old gridlock but raised new questions about democratic oversight of security policy.
A report in February 2022 indicated that Macron’s declassification review had withdrawn only 59 documents out of nearly 35,000.
The global stakes. French nuclear history does not only concern France. France became the world’s fourth nuclear weapon state by building test sites and conducting atmospheric and underground explosions in two former French colonies: Algeria and then Polynesia. These blasts drew criticism from Algerian and Polynesian leaders, and from many neighboring countries in Africa and the Pacific.
Before becoming one of the world’s top nonproliferation cops, France served as a global nuclear supplier. During the Cold War arms race, the French government was among those that provided Israel, India, South Africa, Iran, and Iraq with nuclear technologies. Except for possibly Iran, all these states endeavored to build nuclear weapons; so far, only Iraq has failed to do so.
French nuclear history also has important ties to the United States and its Cold War foreign policy. Despite public refusal to help the French program, the Eisenhower administration invited French officials to the Nevada Test Site and provided diagnostic instruments for use in Algeria. The Kennedy-era State Department participated in Franco-Algerian negotiations over continued French use of the test sites in the Algerian Sahara after Algerian Independence. The Johnson White House took a firmer stance, refusing further nuclear aid to France. Worried about the reliability of France’s nuclear arsenal, President Richard Nixon and his National Security Advisor Henry Kissinger secretly reversed US policy and launched unprecedented Franco-American cooperation on weapons design and safety procedures.
Implications for continental security. French nuclear weapons have special relevance to European integration. Russian President Vladimir Putin’s invasion of Ukraine in February 2022 reignited decades-old proposals, despite their impracticality and unpopularity, for the French nuclear arsenal to provide the basis for a European deterrent. That month, French Foreign Minister Jean-Yves Le Drian suggested on French public television that a Russian nuclear attack on Ukraine could trigger a nuclear counterstrike by French forces and their nuclear-armed Atlantic allies. In July 2022, German politician Wolfgang Schaeuble cited the Russian invasion as a reason for Germany to subsidize the French nuclear arsenal in exchange for French nuclear security guarantees.
These recent statements recall Macron’s speech in February 2020 at the French War College in Paris, where he invited European partners to participate in a “strategic dialogue” about the French nuclear arsenal’s role in their security. Because French leaders have, since the 1960s at least, considered Europe’s defense among France’s vital interests, Macron’s speech did more to bolster a long-standing pillar of French nuclear strategy than to break new ground. It is unlikely that his, Le Drian’s, or Schaeuble’s statements have introduced a new European nuclear security posture.
French nuclear archives can help illuminate longstanding policies and actions of nuclear weapon states, including France and its Atlantic allies, as well as the relevant attitudes of non-nuclear weapon states and non-state actors. For example, new access to documents about Polynesia in the 1970s could shed light on how French nuclear capabilities acquired the credibility—lacking during the 1960s—to serve in the minds of European partners as a cornerstone of the continent’s security. Documents from Nixon’s and Kissinger’s offices have demonstrated US attention to improving the French arsenal’s reliability, but French documents from this era could reveal another side to the story.
Macron’s Declassification Commission. The official origins of the recent Declassification Commission (la Commission d’ouverture des archives des essais nucléaires en Polynésie française) date to July 2021. Macron organized a roundtable event in Paris with Polynesian representatives, including Polynesian President Edouard Fritch, and visited the Pacific islands. In Papeete, Macron announced an unprecedented “opening” of French nuclear archives and tapped his Ministry of Defense in October 2021 to begin the declassification process.
The impetus for Macron’s policy change had arrived earlier. The publication in March 2021 of the French-language book Toxique, by the physicist Sébastien Philippe and investigative journalist Tomas Statius, created a media firestorm surrounding French nuclear history.
Toxique showed that French authorities underestimated and overlooked the extent of radioactive contamination—and the health risks—from the atmospheric explosions conducted in Polynesia until 1974. This finding relied on dozens of French documents declassified in 2012–13, following a decade of court battles fought by associations of nuclear test victims and anti-nuclear organizations.
Macron put the new Declassification Commission under the authority of Geneviève Darrieussecq, French Minister Delegate to the Ministry of Defense for the Memory of Former Combatants. An archivist appointed to Darrieussecq’s cabinet, Marion Veyssière, described the Commission’s work during a seminar in October 2021 held in Paris by the historians Renaud Meltz and Alexis Vrignon, editors of a recent study on French nuclear testing funded by Polynesia’s semi-autonomous government. Two other French archivists, Gilles le Berre and Marion Soutet, described their declassification work during meetings of this seminar.
The Declassification Commission mostly succeeded in working across bureaucratic silos in the French state.
The French military archives (le Service historique de la Défense) are perhaps the largest source of official documents about the development of French nuclear weapons, but researchers had hardly managed to consult it since the early 2000s. Meltz, in his and Vrignon’s 2022 book Des Bombes en Polynésie, uses these recently declassified military documents to explain how French officials chose Polynesia and built the Pacific test site, monitored radioactive contamination, and endeavored to keep much of it secret.
The French military’s multimedia repository (l’Établissement de Communication et de Production Audiovisuelle de la Défense) declassified significant quantities of photographs and videos, and digitized some of these. The French radiological monitoring service (le Département de suivi des centres d’expérimentations nucléaires), which maintains attention to the Pacific test sites, accepts research requests as part of its participation in the declassification process.
The French national archives have made available relevant documents from the files of French presidents and their advisers, state ministries, certain courts, and private collections maintained by public services.
The Division of Military Applications of the French Atomic Energy Commission (CEA-DAM) maintains its own archives but agreed to coordinate with the Declassification Commission. In a parallel process, the CEA-DAM declassified dozens of textual documents, in addition to photographs and videos. Long off-limits for research, the textual documents are available online using a French Defense portal.
Limits to French nuclear transparency. Recent French declassifications indicate real progress, but three shortcomings have become clear.
First, archival documentation of France’s first nuclear explosions in the Algerian Sahara (1960–66) falls outside the Declassification Commission’s mandate. This recent work, as well as the CEA-DAM process, have incidentally declassified a few documents about the two test sites in the Algerian desert. But most of these records remain unavailable for research.
This split in French nuclear history—between Algeria and Polynesia—is artificial. Similar French entities, and often the same French officials, directed the Algerian and Polynesian sites.
The reason for French transparency about the Polynesian sites, but not the Algerian ones, stems from French politics. Polynesia, and its semi-autonomous government, are part of France. Algeria won its independence in a bloody war of decolonization that coincided with the first French nuclear explosions. Algeria remains a touchy subject in France.
Macron’s significant but partial opening of French archives facilitates a national politics of reconciliation, where the French President pays down the “debt” that he says France owes Polynesia by releasing information. As a presidential candidate, Macron controversially described the French colonization of Algeria as a “crime against humanity,” but he has not acknowledged France’s debt for its nuclear arsenal to Algeria or to other African states—many former French colonies—bordering the abandoned test sites.
Second, key French government stakeholders did not participate in the recent declassification process. The Ministry of Foreign Affairs, which maintains its own archives much like the Ministry of Defense, abstained. As a result, crucial documentation of French nuclear weapons development—particularly the diplomatic and political implications—remains unavailable for research. The French Diplomatic Archives want to conduct their own declassification review, I was told, but need a budget to staff this project.
Third, the narrative of transparency that Macron has presented hides some opacity. To assess proliferation risks, the Declassification Commission invited experts from the CEA-DAM for document review. Here, French nuclear planners act as “both judge and jury,” as the French political scientist Benoît Pelopidas puts it. Although this process may have withheld only a small number of the documents reviewed, French officials have not identified the nuclear experts who participated. No independent check on their judgment exists.
On this last point, the nonproliferation language in the 2008 French archive law has not changed. The Declassification Commission chose to interpret it narrowly, but this decision does not bind other French entities to follow suit. One example: The French military archives, which participated in the Declassification Commission, recently cited the 2008 nonproliferation language to block me from even requesting access to a folder about the two Algerian test sites.
Insights from the archives. French President Macron’s shift in declassification policy opens a new window into the development of French nuclear weapons. Researchers can now look to France for resources to understand the nuclear dimensions of European security during a moment when these dimensions have become all too obvious.
What makes France so important? Now the only nuclear weapon state in the European Union, France’s nuclear history has key quirks. It also has global reach.
In contrast to their British neighbors, French officials endeavored to build their nuclear weapons program as independently of the United States as possible. Franco-American technological cooperation improved during the Cold War, but Paris remained committed to charting its own strategic course. France provides a case study of trying to go it alone.
The French case also demonstrates deep entanglement with French colonial policies in Africa and the Pacific. A similar point holds true for the US use of the Marshall Islands as a nuclear test site and tribal lands for uranium mining, or for UK nuclear testing in Australia. As the only country not merely to plan but actually to conduct nuclear explosions on the African continent, and given the longevity of its nuclear presence in the Pacific, France offers a unique vantage point on broader intersections between the Cold War arms race and decolonization struggles.
French nuclear archives have as much to do with today’s politics as with 20th-century history. Macron’s policy shift demonstrates the impact of executive action and the power of civil society to shape nuclear weapons governance when researchers, journalists, activists, and other stakeholders work together. The French case has unique features—namely the legal status of Polynesia—but it holds broad lessons for nuclear-armed democracies.
Building on recent strides, the French declassification effort can expand in ways that do not threaten nonproliferation goals. Two places to start: documentation of the Algerian test sites and the rich nuclear collections in the Diplomatic Archives.