Last month, a senior French official made a subtle policy change with important consequences. On its face, the change seems mundane: Secretary General of Defense and National Security Claire Landais activated an existing rule that requires the formal declassification of every classified document from 1940 to the present. No big deal, right?

Wrong.

This change has already had one profound consequence: The French defense archives on World War II, the First Indochina War, and the Algerian War have effectively been re-sealed. While the rules change was intended to provide greater oversight on the release of documents, the lack of clear directives, the confusion of archivists, and the suddenness of the change have halted all access to these critical records.

For historians, the problems posed by this change seem obvious. In France, archives are governed by Articles L.213-1 and L.213-2 of the Code du Patrimoine, which dictate that most documents be released to researchers and the public after 50 years — a system that works similarly to the U.S. government’s own policies on declassification. Most of the archival collections affected by this change were therefore already open, some for decades, rendering their secrecy moot. The problem now confronting researchers has roots in a second document: the 2011 Interministerial Instruction 1300 on the Protection of Defense Secrets, which governs all classified documents in France. Article 63 of the instruction requires every document classified ‘secret’ or ‘top secret’ to be formally declassified by the agency that produced it before it can be communicated to the public, but because it contradicts the process outlined in the Code du Patrimoine, it has not been enforced. Its sudden and unannounced imposition has left researchers at the Defense Historical Service archives in Vincennes cut off from their sources.

Things seem likely to get worse. Not only does the secretary general’s authority extend to all classified documents and thus in principle to all French archives, but the scale of work implied by formal declassification is staggering. Picking at random from the documents on the Algerian War that I collected over years of research at Vincennes gives us some indication: In one dossier, 62 of 88 documents bore some form of classification. In another, 64 of 78 documents were stamped ‘secret’ or ‘top secret.’ The Ministry of the Armed Forces has promised to hire additional workers to handle declassification, but the process will take years — perhaps decades. Historical societies in France and around the world have objected vociferously to these changes and a petition is circulating. But the future of archival access is deeply uncertain.

This is not just about the parochial concerns of the ivory tower. The archives are also the raw materials for formulating effective policies and military strategies. By erecting barriers to archival access, the French government will stifle critical work on diplomacy, nuclear policy, foreign intervention, and dozens of other critical domains that could inform smarter decisions in the future.

We don’t need to speculate that this will be the case: We have already experienced something similar right here in the United States. In 1999, an amendment to the Defense Authorization Act known as the Kyl-Lott Amendment imposed similarly understated but far-reaching limits on declassification in U.S. archives. In principle, the amendment aimed to protect against the inadvertent release of documents related to America’s nuclear program. This is an entirely legitimate concern. Despite containing highly sensitive information that bad actors might exploit, many documents covering crude nuclear tests in the 1940s and 1950s were not properly classified. What’s more, the federal government never devoted sufficient attention or funding to protecting even those documents that were.

In practice, however, the ambiguity of what constituted the ‘Restricted Data’ outlined by the amendment opened the door for the Department of Energy, the Department of Defense, and other federal agencies to enter the National Archives and presidential libraries and withdraw thousands of documents that were only tangentially related to nuclear weapons from academic and public scrutiny. A 2006 report by the National Security Archive revealed that agencies used the amendment as a pretext to quietly reclassify millions of pages of documents for dubious reasons. The amendment also brought a host of new rules and regulations and shifted declassification from a document-by-document process to a page-by-page one, with no increase in funding to hire additional archival staff. Sound familiar?

These actions have gummed up the declassification process, slowed or halted the work of scholars, and removed crucial documentary records on U.S. weapons programs from public view — often at enormous public expense. In 2009, the Obama administration created a National Declassification Center within the National Archives to restore some semblance of transparency and work through the backlog of documents awaiting declassification. But a decade and millions of pages of documents later, the backlog continues to grow, compounded by the volume of incoming digital materials, the limited technological capacity of the archives, and a general lack of funding. As historian Matthew Connelly recently made clear, the scale of these problems has led the National Archives to delete or destroy rather than preserve critical records for the future. The Pentagon is poised to spend almost unimaginable sums on technological innovation over the next 20 years. Surely policymakers would benefit from a more robust debate and more detailed studies from scholars on what worked — and what didn’t — during the so-called ‘second offset.’

The American experience should thus serve as a cautionary tale for French leaders. In both countries, a lack of clear guidelines or funding for declassification led to a critical lack of oversight and a crisis over documents previously made public. In both countries, the effort to reclassify documents swept up millions of pages of previously published or simply innocuous materials, with no clear oversight mechanism or funding to handle the sheer scale of declassification the rule change implied. And in France, as in the United States, the re-sealing of archives will likely also have a profoundly negative impact on the ability of diplomatic and military historians to glean critical insights from the past that could help officials in the future.

It is here, I would argue, that the costs of reclassification most clearly outweigh the benefits. French defense officials have provided no clear reason for the change other than citing to the need to follow the rules imposed by Interministerial Instruction 1300. But sealed archives are part of the reason why conversations about past conflicts like the Algerian War have seldom moved beyond deeply partisan political debate into close analysis of the social, political, and operational dynamics that shaped their outcome.

Confronted by low-intensity conflicts in Afghanistan and now in the Sahel, the French Army has dusted off and re-evaluated colonial-era doctrines in order to think about what lessons they might apply to ongoing operations. But figuring that out what lesson can or should be drawn from these doctrines requires deep engagement with the historical sources and critical debate over what they can reveal.

Even now, nearly a decade after the Code du Patrimoine finally opened the archives of the Algerian War, scholars and foreign military officers have only just started to scrape the surface of the conflict’s massive archival record for the important lessons that lay beneath. As I have argued in these pages before, texts written by French officers in the 1950s and 60s cannot be taken as straightforward, factual manuals for waging counterinsurgency, but ought to be read as aspirational works intended to persuade outside observers that the French Army had developed novel techniques for waging unconventional wars.

Likewise, even a perfunctory glance at data collated by the French Army in the midst of the Algerian War suggests that long-held assumptions about the conflict — like the aphorism that the French Army won the war militarily but lost politically — are not necessarily borne out by the wealth of data sitting un-analyzed in the archives. As my own research shows, faulty assumptions about the nature of the Algerian Revolution ultimately proved fatal for the French war effort by 1962. Cutting off the critical gaze cast on the archives by scholars and others working outside the military establishment risks trading critical (if sometimes painful) insights into France’s own past for institutional parochialism. Vital lessons will remain unlearned.

As Joshua Rovner recently argued in these pages, secrecy is important. It improves statecraft, facilitates diplomacy, and helps control escalation. But leaned upon too heavily, state secrecy can hobble. And it is unclear how re-sealing archival documents on the Normandy invasion in 1944 or the defense of Dien Bien Phu — documents that have been open for decades — benefits French security. What is clear, however, are the dangers that such a move implies. Just as good history requires meticulous archival research, strategic innovation requires careful consideration of the past. By imposing new restrictions on access to classified documents, the French state jeopardizes both.

Terrence Peterson is assistant professor of history at Florida International University. He is currently finishing a book on the theory and practice of French counterinsurgency in the Algerian War.

Image: Wikicommons (Photo by Guilhem Vellut)