Although they’re portrayed as leaking twins, both in their 20s, Manning and Snowden robbed the secret works of two different classes of classified material. Although Manning held a Top Secret clearance, like 1.4 million other people, none of the hundreds of thousands of files he leaked to Julian Assange’s WikiLeaks organization were of the Top Secret grade; he shared Confidential and Secret pages exclusively. Snowden, on the other hand, gave Top Secret documents to The Washington Post and The Guardian from the very beginning. Manning’s leaks revealed the contents of State Department diplomatic cables, dossiers on the detainees at Guantánamo Bay, and incident reports from the wars in Iraq and Afghanistan—hundreds of thousands of documents constituting the government’s paper trail. While the Manning leaks were stoppered at several hundred thousand documents and their effect contained, Snowden’s ongoing leaks vex the government at a higher level—because he’s still sharing stuff and because his leaks expose the very architecture of the NSA’s global surveillance machine.

Both leakers have been called traitors and accused of weakening their country. In late 2010, shortly after WikiLeaks steered Manning’s leaks to The New York Times, The Guardian, and other outlets for publication, Secretary of State Hillary Clinton denounced those leaks as “an attack on America” and “the international community.” Manning was eventually convicted of espionage and other charges, but US officials conceded privately several weeks after Secretary Clinton’s blast that the harm had been minimal. In a puckish column, the Financial Times’ Gideon Rachman declared that the Manning disclosures had done the United States a great favor. Far from damaging the State Department’s credibility by disclosing its internal discussions, the leaks demonstrated the consistency of its diplomats’ public and private statements. Assange deserved a medal, Rachman suggested, because the diplomatic cables depict American foreign policy as principled, intelligent, and pragmatic. “That was, perhaps, the best-kept secret of all,” he wrote.

There’s no such perverse comfort to be found in the Snowden materials. They portray a deceitful government, sluicing into view the blueprints for the surveillance state. The leaks flow on as I write this, including details about the successful efforts of the NSA to compromise cryptography in our computers and phones and undermine security on the internet. The NSA’s surveillance operations, a foreign and domestic hydra, qualifies as the “vast secrecy system almost wholly hidden from view,” to select one of Moynihan’s salient phrases. In their haste to contain the Snowden revelations, the nation’s leaders have repeatedly lied to the public about what telephone and email messages they intercept, store, and read, and how that information is used.

“Secrecy is a form of regulation,” Moynihan declares in his opening sentence, restricting what information citizens may possess about their government and the actions performed in their name. Unlike economic regulation, whose dimension can be gleaned from reading the US Code and scanning the Federal Register, the shadow cast by secrecy is fundamentally unknowable to few outside the government elite. Writing elsewhere, Moynihan stated, “Normal regulation concerns how citizens must behave, and so regulations are widely promulgated. Secrecy, by contrast, concerns what citizens may know; and the citizen is not told what may not be known.

On occasion, the national security establishment will even prevent the president of the United States from being read in on the secrets elemental to the performance of his office. In the late 1940s, the US Army’s Venona project cracked the codes the Soviet Union was using to communicate with its spy network in America, Moynihan reported. The decryptions were shared with fbi Director J. Edgar Hoover and other members of the national security brotherhood, but General Omar Bradley concealed them from President Harry S. Truman because his White House was known to leak. Venona gave an accurate picture of Soviet penetration of the US. Had the secrets been made public—the Russians had learned by then that they’d been found out—the nation might have been spared the poisonous squalls about domestic communism exhaled by Senator Joseph McCarthy. Of the Venona decryptions, that were finally made public in the mid-1990s, Moynihan writes:

Here we have government secrecy in its essence. Departments and agencies hoard information, and the government becomes a kind of market. Secrets become organizational assets . . . . In the void created by absent or withheld information, decisions are either made poorly or not made at all. What decisions would Truman have made had the information in the Venona intercepts not been withheld from him?

Jack Shafer writes a column about the press and politics for Reuters.