Four pages of the Mueller report lay on a witness table in the House Intelligence Committee hearing room last week. (Cliff Owen)

Adam B. Schiff, a Democrat, represents California’s 28th Congressional District in the House and is chairman of the Intelligence Committee.

Special counsel Robert S. Mueller III’s report chronicles a “sweeping and systematic” Russian effort to interfere in the 2016 election in favor of Donald Trump. It details a damning web of contacts between Russian actors and a Trump campaign that welcomed and sought to capitalize on the interference, as well as an out-of-control president determined to obstruct the investigation.

Yet, as I read the report, I was struck by how much was missing: the enormous counterintelligence and national security risks and ramifications of the president’s conduct and those around him.

The special counsel’s investigation began as a counterintelligence investigation by the FBI into an attack by a hostile foreign power. Yet the report describes the counterintelligence component only in a single paragraph, describing how the special counsel’s office met regularly with the FBI Counterintelligence Division and even embedded counterintelligence agents for the express purpose of ensuring that the FBI captured the foreign intelligence and counterintelligence information uncovered during the investigation. The work of those agents and their findings are not detailed in the report.

What did these counterintelligence agents under Mueller’s supervision uncover? What national security vulnerabilities did Russia’s covert campaign expose? Did any Americans present an acute counterintelligence risk? And what steps, if any, have been taken to address these threats?

Counterintelligence investigations differ from criminal investigations in their means, scope and ultimate disposition. Their goal is not successful prosecutions, but to identify and mitigate threats to national security. If a foreign power possessed compromising information on a U.S. government official in a position of influence, that is a counterintelligence risk. If a foreign power possessed leverage, or the perception of it, over the president, that is a counterintelligence nightmare.

Evidence developed during a criminal investigation can be vital for a counterintelligence investigation, and it need not be classified. For instance, the Mueller report confirms what we learned through the guilty plea of the president’s former personal attorney, Michael Cohen. Trump claimed during his campaign, “I have nothing to do with Russia,” but he was in fact pursuing a real estate deal worth hundreds of millions to build a Trump Tower in Moscow through at least June 2016, and Cohen even sought the assistance of one of Vladimir Putin’s closest aides to consummate the deal.

This scenario presents at least two acute counterintelligence dangers: First, the president’s personal financial interest in the deal and the need for Kremlin approval create an overwhelming conflict of interest. If the Trump Organization believed Putin’s approval was necessary to make a fortune, does this explain why the president is loath to criticize Putin in any way?

Second, the president’s deceit about the project, and Russia’s knowledge of it, give Russia something to hold over him. And yet, questions remain about the Russians on the other end of the deal — their aims, intentions and connections to the Russian government. What other counterintelligence vulnerabilities did the special counsel and FBI identify?

The National Security Act requires that the House and Senate Intelligence committees be kept “fully and currently informed” of significant intelligence and counterintelligence activities. There is no activity more significant than an investigation to determine whether a foreign power exercises leverage over the president or his inner circle.

Within days of the attorney general’s announcement that Mueller had completed his work, Rep. Devin Nunes (R-Calif.), the ranking Republican on the House Intelligence Committee, joined me in writing to the Justice Department and FBI to request not just the full Mueller report and underlying evidence, but all foreign intelligence and counterintelligence information developed in the course of the investigation. Nunes and I agree on very little when it comes to the Russia investigation, but we do agree on this, and that says something. The committee also needs to hear from Mueller and other key players directly, including FBI Director Christopher A. Wray, Deputy Attorney General Rod J. Rosenstein, Director of National Intelligence Daniel Coats and relevant members of Mueller’s team and the intelligence community.

But the committee cannot rely solely on the narrow scope of Mueller’s investigation to develop a full picture of the counterintelligence risk. At the beginning of the investigation, the president sought to draw a “red line” around his finances. It appears this red line held, as Mueller’s report did not address the president’s finances.

Many Americans have expressed deep concerns that foreign powers — especially Russia — cultivated or possessed financial leverage or influence over President Trump or his associates. The president’s unwillingness to be transparent about his finances makes the problem worse. And the president’s behavior toward Putin, including at their 2018 summit in Helsinki, has only heightened the country’s alarm.

Congress must ensure that this administration is not for sale and take all steps necessary to counter foreign influence, including through legislation. For that reason, the House Intelligence, Financial Services and Oversight committees have subpoenaed relevant financial records.

Make no mistake — the release of Mueller’s report is a watershed event. Now, it is up to Congress to assure that the president and his associates work for the American people and not for some undisclosed personal or foreign interests.