Carter Page, a former adviser to President Trump, speaks in Moscow in July 2016. (Pavel Golovkin/AP)

John McLaughlin teaches at the Johns Hopkins University School of Advanced International Studies. He was deputy director of the CIA from 2000 to 2004, and served as acting director in 2004.

When a big, black SUV would pull up to my house at about 2 a.m., I knew it would be awhile before I would be getting back to sleep. As the CIA’s deputy director, and later acting director, in the early 2000s, I was frequently awakened via secure communications at home. But when a car showed up, it meant that something needed my official signature — usually a warrant request under the Foreign Intelligence Surveillance Act, or FISA. The FBI would be asking me to sign off because the request contained foreign intelligence material, often relating to a terrorism suspect.

These things typically ran 40 to 60 pages. They would contain reporting from human sources (foreign agents), technical intelligence such as intercepted communications, and open-source material. These were woven together into a request aimed at showing “probable cause” to investigate further by carrying out some kind of search.

This is the kind of document President Trump is now proposing to make public. He has directed declassification of the FBI’s FISA request for further investigation of Trump associate Carter Page, among other documents. He and his Republican allies have long maintained that this October 2016 warrant was constructed unfairly with the intention of deceiving the Foreign Intelligence Surveillance Court judges into granting the request inappropriately.

In an earlier go-round, Rep. Devin Nunes (R-Calif.), chairman of the House Intelligence Committee, failed to persuasively make that case. He and his colleagues put out a memo in February claiming that the FBI kept from the court knowledge that one of the reports, the so-called Steele dossier (asserting that Russia wanted to help Trump win the presidency), was partly the product of Democratic Party opposition research. When the Democrats gained access to the FISA request and issued a competing memo, however, they were able to prove this was not so. They pointed out that the FBI had acknowledged in the document that the dossier had been commissioned for political purposes. So it is entirely possible that revealing more of the warrant request will once again fail to strengthen the president’s case.

Here are three important consequences if Trump persists and uses his executive power to fully declassify the warrant request — with no redactions.

First, sensitive sources, human and technical, would be exposed. The message to other intelligence services and to specific sources would be that you can’t trust the United States to protect secrets. Our own intelligence and law enforcement services would be demoralized by the president’s political use of their hard-won intelligence.

Second, the nature of these warrant requests is such that revealing this one would not quell controversy. Few people understand that these are investigative tools, not prosecutorial documents. They are not designed to prove guilt or innocence. They pull together reports that suggest a concerning pattern, and the judges have to decide whether the information is sufficiently compelling to justify further investigation with tools, including wiretaps, that require court approval. In other words, law enforcement is not saying it is absolutely certain — it is asking for permission to find out.

Third, tossing such a sensitive, complex and lawful investigative tool into a hot political controversy would be totally irresponsible. Coming in the midst of a law enforcement investigation that involves the president himself, it would amount to his most damaging attack so far on our judicial, law enforcement and intelligence systems.

That would multiply the collateral damage already created by this controversy. Intelligence oversight, one of Congress’s most important duties, has been weakened. It is effective only when carried out in a bipartisan way. While the Senate Intelligence Committee appears to be functioning well and with bipartisan spirit under Republican Chairman Richard Burr (N.C.), the House committee has seldom been more divided. When the majority released the aforementioned memo on the FISA warrant in February, it did so without minority comment or a contemporaneous minority dissent. I’m not aware of this ever happening with intelligence oversight in the past.

Regarding Trump’s declassification request, my hunch is that responsible leaders of agencies will play this by the book, which means that agencies contributing material to the warrant will do yet another formal classification review. It will come back with lots of blacked out passages — redactions. If the president overrides his professional staff and insists on unredacted declassification, it would force some officials, sworn to protect sources and methods of intelligence and law enforcement, to consider resignation.