The 37-count indictment of former President Donald Trump on federal charges of willfully retaining documents containing national defense information, refusing to return them, and obstructing related investigations, is a watershed moment. The implications are grave not just for the former president – they also serve as a litmus test for the rule of law and the democratic institutions charged with upholding it. The fact of this indictment is an important testament to the principle that no person, not even a former president, is above the law in a democracy; likewise, the process that follows will be a test of the constitutional requirement that all defendants, including Trump, are entitled to the law’s evenhanded application.

As if that were not enough, even more is at stake in this case. Because of the remarkably sensitive nature of the documents the former president retained, and the shockingly insecure locations where they were held and transported (“in a ballroom, a bathroom and shower, an office space, his bedroom, and a storage room”), there are also potentially grave implications for U.S. national security. It is those national security implications, as evidenced in particular by the 31 counts lodged under the Espionage Act (18 U.S.C. § 793(e)), which we briefly lay out here.

What We Know and How We Know It

At issue in the indictment are scores of classified documents the former president stored at his Mar-a-Lago club in Palm Beach, Florida, covering a wide range of sensitive national security information. The indictment states that these documents impact the equities of several U.S. intelligence agencies, including the CIA, National Security Agency, Department of Defense, Department of Energy, National Geospatial Intelligence Agency, and the State Department’s Bureau of Intelligence and Research. The indictment reads:

“The classified documents Trump stored in his boxes included information regarding defense and weapons capabilities of both the United States and foreign countries; United States nuclear programs; potential vulnerabilities of the United States and its allies to military attack; and to plans for possible retaliation in response to a foreign attack.”

Military plans and capabilities, for example, are some of the most zealously guarded secrets a government can hold, because the compromise of that information can put at serious risk any military operations – and the lives of members of the armed forces – related to those plans or capabilities.

It is also important to pay attention to the classification markings on the documents at issue in the 31 Espionage Act counts. These markings reflect not just the level of sensitivity of the information, but are often used to indicate how the government knows the information contained in the document. Some of the documents listed in these counts bore markings indicating that the information was derived from human intelligence (HUMINT), signals intelligence (SIGINT), and sensitive imagery collection, while other information was collected under the Foreign Intelligence Surveillance Act (FISA). That means their compromise could risk not just exposing the information in the U.S. government’s possession, but the sometimes extremely sensitive sources and methods used to collect it.

Of particular concern is that, in addition to Top Secret information (which means its unauthorized disclosure could reasonably be “expected to cause exceptionally grave damage to the national security”), the documents likely contained what is known as codeword material, the highest level of classification in the U.S. government and restricted to a small list of named individuals with a “need to know.” As the indictment explains:

“When the vulnerability of, or threat to, specific classified information was exceptional, and the normal criteria for determining eligibility for access to classified information were insufficient to protect the information from unauthorized disclosure, the United States could establish Special Access Programs (“SAPs”) to further protect the classified information. The number of these programs was to be kept to an absolute minimum and limited to programs in which the number of persons who ordinarily would have access would be reasonably small and commensurate with the objective of providing enhanced protection for the information involved. Only individuals with the appropriate security clearance and additional SAP permissions were authorized to have access to such national security information, which was subject to enhanced handling and storage requirements.”

These codewords have been redacted from the indictment because even the codewords themselves are considered to be highly classified information. Yet the SAP documents were handled, stored, and potentially discussed at a golf club and resort that regularly hosts foreign visitors and large events.

Given the indictment lists only 31 of the classified documents Trump retained, we don’t know whether this is just the tip of the iceberg. Indeed, some of the others may very well have been far too sensitive to use in a public trial.

What Could be Lost

Compromising these types of intelligence streams could lead to an irreplaceable loss of technical or human access that took years and significant resources to develop. And that also entails a corresponding loss of insight into sensitive programs, leadership dynamics, and intent on the part of foreign governments (including adversarial ones) and their leaders. Some of the implicated intelligence streams could also be crucial for the defense of the United States, its allies, and its forces abroad. In short, as the indictment states, these disclosures “could put at risk the national security of the United States, foreign relations, the safety of the United States military, and human sources and the continued viability of sensitive intelligence collection methods.”

Beyond compromising U.S. information, the security breach is significant because of its potentially damaging impact on intelligence liaison relationships and information sharing with other countries. If the documents contained information from joint collection streams, for example, it is possible that the former president has compromised allied governments’ sources and methods. As an example, some of the documents were marked “FVEY,”(or “Five Eyes”), indicating that they were shared with U.S. intelligence partners in Australia, Canada, New Zealand, and the United Kingdom.

The indictment details at least two instances of “TRUMP’s Disclosures of Classified Information in Private Meetings,” in unsecure locations, in which he knowingly shared classified information with people who did not have security clearances. Did he knowingly or unknowingly share any of this information with individuals who could have been agents of a foreign power, or with others who did so in turn? It is not inconceivable that foreign intelligence agencies – who would go to great lengths to access information of exactly this sort – could have gained access either to the documents themselves (were the boxes in the Mar-a-Lago ballroom, for example, left there during events?), by initiating a relationship with Mar-a-Lago staff who had access to the documents, or others in Trump’s orbit to whom he showed or described the documents.

Since these scenarios are plausible, the Intelligence Community may now be in the unfortunate position of having to assume the compromise of some of this information and needing to mitigate the potential fallout, which could entail dropping crucial programs or sources. (Indeed, the Intelligence Community may have needed to do so as soon as it was discovered that some of these documents were missing, which could explain a willingness to now use them in trial if certain intelligence streams are no longer active.) It is also possible that the Intelligence Community has not yet discovered all the missing classified documents, which poses a risk that some intelligence streams could be compromised without U.S. government knowledge (and be used to conduct denial and deception campaigns, for example).

Finally, it merits mention that there is nothing in the indictment or otherwise indicating that the U.S. government is now sure it has recovered all of the classified information. Trump may have retained more documents when he left the White House. We do not know whether he has additional documents or materials that he might have brought with him, or lost control of them. Think, for example, of the recent reports that Trump’s lawyers cannot find the “Iran attack plan” document that we now know, from the indictment’s recounting of a recorded, previously-reported exchange about the document among Trump and various aides and book writers, that both Trump and the government consider a classified document. For national security officials, knowing that we don’t know whether there are more classified documents, or more instances of disclosing the known documents, is a remaining serious concern.

Image:  In this photo illustration, pages are viewed from the unsealed federal indictment of former U.S. President Donald Trump on June 9, 2023 in Washington, DC. Former U.S. President Donald Trump has been indicted on 37 felony counts in Special Counsel Jack Smith’s classified documents probe.(Photo Illustration by Drew Angerer/Getty Images).