Opening the JFK files would have been a triumph of transparency. If only.

America waited 25 years for what came on Thursday, and it could have been worth it.

In 1992, Congress decreed that every secret file in the investigation of the assassination of President John F. Kennedy should become public on Oct. 26, 2017.

The National Archives was so bombarded by inquiries that it stopped answering them. JFKfiles was trending on Twitter, and President Donald Trump himself stoked the drama, saying Wednesday that he would release the files and that they were "So interesting!"

Then, late in the day came word that the big reveal would fall short. Under pressure from the CIA and the FBI, the president said he had "no choice" but to keep an unspecified number of records off-limits while the agencies spend another six months poring over them for national security pitfalls.

What could have been a triumph for transparency instead confirmed to the cynics and conspiracy theorists that the government can never come clean.

John Tunheim, chief federal district judge in Minnesota, doesn't believe that any of the withheld records would substantially change the public's understanding of that day in 1963 in Dallas. He should know. He's seen them all — every one — when he headed the powerful panel set up by Congress in the 1990s to declassify the hundreds of thousands of pages of JFK files.

In an interview Friday, Tunheim said he found the position of the CIA and FBI "disappointing" and "shortsighted" and said it should have been an "easy call" to release all of the records.

"There's great value in telling the American people that nothing's being hidden from them," Tunheim said.

Having had 25 years to make its case, the CIA felt it had to explain why it needed six more months. So it issued a rare statement Thursday indicating that "[e]very single one of the approximately 18,000 remaining CIA records in the collection will ultimately be released, with no document withheld in full."

The statement said the CIA wanted to withhold information only to protect national security, "including the names of CIA assets and current and former CIA officers, as well as specific intelligence methods and partnerships that remain viable to protecting the nation today."

Tunheim has heard those arguments before. He doubts there are any CIA agents or sources still alive or active today who need protection. The only plausible argument in his mind are records that describe intelligence agreements that the United States had with foreign governments, and those aren't really directly relevant to the assassination anyway.

Thanks to the efforts of Tunheim's panel, thousands of records have been released over the years, and researchers pored hungrily over the 2,800 records posted to the National Archives website Thursday.

Missing from the release were some of the more highly anticipated records: a full account of Lee Harvey Oswald's trip to Mexico weeks before the assassination, as well as the personnel file of CIA officer George Joannides, whose work in Miami could have put him in contact with Cuban exiles monitoring Oswald.

In a Friday tweet, Trump promised that "In the end there will be great transparency. It is my hope to get just about everything to public!"

If that ever happens, it could start healing the 54-year-old wound inflicted by government secrecy. In Tunheim's view, the government could finally say: "People can go see and decide for themselves. … Here it is, here's the whole file. Nothing is hidden anymore."

Contact James Eli Shiffer at james.shiffer@startribune.com or 612-673-4116.