IN RECENT DAYS, President Obama and Attorney General Eric H. Holder Jr. have acknowledged that prosecutors may have overreached in two leak investigations which obtained phone call and e-mail records of journalists. It’s good to see them stepping back from the brink. As the president put it in his address at the National Defense University, a free press is essential to democracy, and “journalists should not be at legal risk for doing their jobs.”

Mr. Obama ordered a review of existing Justice Department internal guidelines on leak investigations, and Mr. Holder began holding consultations with editors. The guidelines were last approved in 1980, and a review is overdue. We hope it can clarify the government’s obligation to notify the news media in advance, if possible, when it seeks such sensitive items as phone records and e-mails.

Unfortunately, we need more than just a few tweaks to policy guidelines. The United States government faces a much larger and more profound problem with secrecy that undermines much of the debate about what should properly be kept quiet and what should not. That problem is simply that too much information is classified. Some 4.8 million people, both government employees and contractors, have access to classified material, labeled confidential, secret or top secret. The colossal system has turned into a Hoover Dam blocking important information about government decisions. In a report to Mr. Obama last November calling for reform, the Public Interest Declassification Board said current classification practices are “outmoded, unsustainable and keep too much information from the public.” One intelligence agency alone is accumulating a petabyte of classified records every 18 months — equivalent to 20 million four-drawer filing cabinets filled with text, the board found.

We endorse the need to keep some things under wraps, like intelligence sources and methods or ongoing operations, and we believe that laws and rules are the proper way to keep secrets. But very often, the only way important information reaches the American people is through leaks — by government employees, including very high-ranking officials, who discuss sensitive information with reporters because they believe it is critical to understanding decisions, or they want to influence those decisions. It’s essential not to criminalize this process; more leak investigations will only serve to dry up the vital flow of information to reporters and the public. It seems out of whack that prosecutors are on the prowl for leakers yet the massive system of over classification lumbers on, unhindered. No one in Washington is ever punished for needlessly stamping “secret” on a document.

Consider this: The total number of nuclear warheads in the U.S. stockpile was declared a secret for many years. Then in 2010, the totals were disclosed through 2009. Did the sky fall? No. For a long time, the top-line budget number for the national and military intelligence programs were kept secret. Then they were disclosed. Did our spy agencies come apart at the seams? No. Is the United States more vulnerable after the president declassified details about the CIA drone killing in 2011 of Anwar al-Awlaki, a U.S. citizen working for Yemen-based al-Qaeda in the Arabian Peninsula? Hardly. Mr. Obama has pledged to be a paragon of openness without risking national security. His record so far is quite mixed. He ought to focus on the big picture: How to restore respect to a dysfunctional system.