According to Attorney General William Barr, the Mueller team concluded that it “did not establish that members of the Trump Campaign conspired or coordinated with the Russian government in its election interference activities.” Assuming that Barr has not misquoted Special Counsel Robert Mueller—and I am confident he has not—I am not terribly surprised that the investigation produced this result. Nor am I surprised that President Trump and his allies are declaring total victory, after a concerted public relations campaign to define success on terms they were always likely to satisfy.

I am, however, surprised that some media commentators have mischaracterized this declination decision as total and complete absolution of the Trump campaign. Some headlines have declared that Mueller found “no evidence” of collusion or coordination. But as Paul Rosenzweig has pointed out, federal prosecutors will not return an indictment unless, among other things, they believe the admissible evidence will establish guilt beyond a reasonable doubt.

The reason for my surprise, perhaps better characterized as disappointment, is not just that these descriptions of “no collusion” ignore the plain text of the Barr summary—not to mention the extensive body of information about contacts between the Trump campaign and Russia in Mueller charging documents and in other press reports, much of it catalogued here by House intelligence committee Chairman Adam Schiff. Rather, I am disappointed because these reports miss the most important point of all of this: The special counsel’s prosecution and declination decisions tell only a small part of the story that all Americans, and their elected representatives, should care deeply about. After all, criminal culpability is not the standard by which someone’s fitness to be elected to the office of president of the United States, or in this case to remain in that office, should be judged. As some observers have correctly explained in recent days, this distinction goes to the heart of the difference between a criminal investigation, on the one hand, and a counterintelligence investigation, on the other. Barr’s summary speaks only to the former and omits any facts, findings or conclusions from the latter. Counterintelligence is always where the action was going to be.

According to some reports, the Department of Justice does plan to brief the congressional intelligence committees on its counterintelligence findings. This is not terribly surprising in light of the obligation, under 50 U.S.C. § 3092, to keep the congressional intelligence committees currently and fully informed of all intelligence activities. As this aspect of Mueller’s work plays out in the coming months, it is worth unpacking some of the primary distinctions between these criminal and counterintelligence investigations, to understand both the potential importance of the information that remains hidden and what the public can expect from it when it emerges.

As the Mueller investigation demonstrated, the two types of probes are indistinguishable at the investigative stage. The FBI’s internal guidelines explain this clearly:

While some distinctions in the requirements and procedures for investigations are necessary in different subject areas, the general design of these Guidelines is to take a uniform approach wherever possible, thereby promoting certainty and consistency regarding the applicable standards and facilitating compliance with those standards. Hence, these Guidelines do not require that the FBI’s information gathering activities be differentially labeled as “criminal investigations,” “national security investigations,” or “foreign intelligence collections,” or that the categories of FBI personnel who carry out investigations be segregated from each other based on the subject areas in which they operate. Rather, all of the FBI’s legal authorities are available for deployment in all cases to which they apply to protect the public from crimes and threats to the national security and to further the United States’ foreign intelligence objectives. In many cases, a single investigation will be supportable as an exercise of a number of these authorities—i.e., as an investigation of a federal crime or crimes, as an investigation of a threat to the national security, and/or as a collection of foreign intelligence.

However, they diverge in important ways when it comes to their purpose. In the criminal context, the investigation is ultimately focused on an enumerated list of carefully defined activities—and the requisite state of mind—that are proscribed by statute. The range of conduct that can be prohibited by criminal statute is limited by, among other things, the Constitution—for example, the vagueness doctrine, which requires a statute to state clearly and explicitly the conduct that is prohibited—and the ability of Congress to foresee the possibility of certain harmful conduct. The criminal code is not necessarily comprehensive when it comes to prohibiting conduct that society finds morally or ethically reprehensible, or even a potential threat to American interests or national security. A counterintelligence investigation, on the other hand, has a different purpose or objective—to identify and mitigate threats posed by foreign governments. In other words, such investigations have a broader focus, and their implications are potentially far more concerning from a national security standpoint. Just because someone is not (yet) a criminal does not mean he or she is not a threat.

The evidentiary standards are quite different. In the criminal context, the government must prove each element of a criminal offense beyond a reasonable doubt. Certain forms of evidence, such as hearsay, are inadmissible. And even when the government possesses evidence that can meet those standards, the level of transparency associated with criminal trials sometimes causes the government to forego prosecution to protect sensitive intelligence. In a counterintelligence investigation, however, the government can look at—and make judgments based on—the full body of information in its possession. Despite its imperfections (to say nothing of the criminal justice system’s own propensity to produce wrong results), there are things that, from an intelligence perspective, the government knows or believes with high confidence that it cannot—or chooses not to—prove in a court of law.

The Mueller investigation has always been both a counterintelligence and a criminal investigation. In his initial appointment order, Mueller was charged with investigating Russian election interference, including any “links and/or coordination between the Russian government and [the Trump campaign].” Acting FBI Director Andrew McCabe, on his own account, authorized a counterintelligence investigation of Trump himself in the wake of the firing of FBI Director James Comey.

In light of press reports about the gradual expansion of the Mueller inquiry and its offshoots, including into the president’s personal finances and business relationships, this was not terribly surprising. The steps taken by McCabe in the summer of 2017 are probably best understood as an expansion of the ongoing counterintelligence investigation, to include a broader set of motivations for seemingly troubling and inexplicable behavior on the part of the president. The question, it appears, was not merely whether the president was attempting to obstruct the investigation to cover up so-called “collusion” but also whether there were any corrupt motivations for such obstruction—including any conceivable motives for Trump to assist or protect Russia. It is not clear how far the FBI got in this investigation or whether it was assigned to Mueller’s team after the special counsel was appointed—and, if so, whether the special counsel chose to continue this aspect of the probe. However, if done correctly, the investigation would ask a broad set of questions, including: What motivations might Russia have to help Trump get elected? Are there any reasons Trump might be a witting or unwitting Russian agent, or vulnerable to manipulation by Russia? Though Mueller’s investigation would have certainly been gathering information relevant to this inquiry, it is reasonably clear that the other ongoing investigations spun off from the special counsel to U.S. attorneys’ offices could also bear on these question.

When authorized investigative steps run their course in the criminal context, prosecutors generally decide whether or not the evidence can support criminal charges. (This is a slight oversimplification; for a fuller, more nuanced discussion of how these decisions are made, see this excellent summary.) Counterintelligence investigations, on the other hand, do not always produce definitive conclusions. Many cases fall into a squishy middle area, leaving national security professionals to decide what to do based on the nature and significance of the potential threat and the level of confidence in the intelligence community’s overall assessment.

In other words, it is conceivable that the counterintelligence investigation into the president remains open. And even if it has been “completed” and the Mueller report contains a summary of the counterintelligence investigation, do not expect it to yield clear answers.

The range of appropriate remedies can differ between criminal and counterintelligence investigations. Again, the Mueller investigation has illustrated the potential remedies available in the criminal context. Counterintelligence investigations can often require noncriminal solutions. In espionage cases, for example, criminal prosecution is only one of several potential remedies to mitigate the threat that individual poses. Someone who cannot be charged, but is believed to be working on behalf of a foreign power, may be subjected to constant surveillance, approached in an effort to convince him or her to flip, or even expelled from the country.

If the counterintelligence investigation produces significant derogatory information or a troubling assessment against the president, the inability to hold him criminally responsible does not leave the country powerless. In fact, the Constitution provides for two noncriminal remedies for dealing with potential counterintelligence threats in the Oval Office. The first comes in the form of Congress’s impeachment and removal power. The second comes in the form of four-year terms of office.

Though there is some disagreement among legal scholars, I am in the camp that believes the exercise of the impeachment and removal power is not limited to criminal conduct. It is, instead, a political process. The odds here work in President Trump’s favor. He has spent the past two years speaking directly to his base, appealing to a fact-challenged cadre of supporters to insulate himself politically. Though it is still conceivable that the contents of the Mueller report could prompt the House of Representatives to impeach Trump, it is hard to imagine that it could cause enough Republican senators to overlook the political ramifications and vote to convict him.

Instead, as many have long suspected, the reckoning for Trump is much more likely to come in the form of the 2020 presidential election. For the process to function as designed, the country needs a well-informed public. The series of indictments, guilty pleas and convictions produced by the special counsel helped to tell part of the story of what happened surrounding the 2016 election. The summary of Mueller’s prosecution and declination decisions was also necessary but is not sufficient. The Mueller report, as well as the results of the counterintelligence aspects of the investigation, must be made public so that the American people can make an informed decision when choosing their next president.

The House of Representatives will play a critical role in determining whether, and to what extent, that happens. The House has broad powers to compel disclosure of information, including classified information, that is necessary to carry out its legislative and oversight functions. It may not be able to get that information without a fight, and that fight will take time. But members of Congress can make a very strong case that, legally, they should prevail. Whatever the end result, it is a battle that is worth fighting. In light of the possibility that Mueller’s team uncovered significant derogatory information about the president and his inner circle, Congress cannot simply ignore the potential ramifications for American security, even if criminal offenses “cannot be established.” The stakes—for the rule of law and for American security—are simply too high.