A Nixon subordinate said that the former president didn’t know half the things his intelligence agencies were doing that fell outside the law. (Charles Tasnadi/AP)

We now know that President Obama's assurances that the NSA wasn't "actually abusing" its surveillance programs are untrue. A leaked audit shows the NSA violated its own privacy rules, and in some cases the law, thousands of times over a one-year period.

A lot of people are assuming this means the president was lying — that he's known about the scale of the NSA's privacy problems all along and was trying to mislead the public. But there's another possibility that could be even more troubling: He might not have known about the extent of the NSA's privacy problems until this week.

It's not as far-fetched as it sounds. We know that Diane Feinstein (D-Calif.), the chairwoman of the Senate Intelligence Committee, only learned about the NSA privacy audit when The Washington Post asked her staff about it. And the chief judge of the Foreign Intelligence Surveillance Court has admitted that the court has limited ability to police NSA misconduct.

Moreover, an internal NSA document Edward Snowden provided to The Washington Post advises NSA analysts that "while we do want to provide our FAA overseers with the information they need, we DO NOT want to give them any extraneous information." The "overseers" are the Office of the Director of National Intelligence and the Department of Justice. The NSA may not have been giving the full story to the attorney general and the director of national intelligence. And they, in turn, might have had reasons to keep some details about the extent of NSA abuses to themselves.

It's happened before, as I wrote last month:

[In a 1975 hearing], a White House aide who had planned a controversial domestic surveillance plan in the Nixon administration testified that the White House “didn’t know half the things” intelligence agencies were doing that might be legally dubious.

“If you have got a program going and you are perfectly happy with its results, why take the risk that it might be turned off if the president of the United States decides he does not want to do it,” he asked.

Secrecy also makes it easier for executive branch officials to cut legal corners on otherwise legal programs. For example, the Patriot Act gave the Bush administration broad authority to issue National Security Letters, secret requests for information that don’t require judicial oversight. But a 2007 Inspector General’s report found more than 700 cases where FBI agents who didn’t have the authority to issue NSLs had improperly obtained information by telling companies that “exigent circumstances” required that the information be turned over immediately, without even the minimal checks required by the NSL rules.

Transparency and rigorous oversight protect the public against malevolent presidents who compile enemies lists and spy on their political opponents. But almost as important, transparency also protects honest presidents against misbehaving subordinates. The knowledge that their work will be checked by judges and Congressional investigators gives government employees a strong incentive to follow the law. And the knowledge that their misconduct will eventually be discovered by other branches of the government make it less tempting for executive branch officials to hide misconduct from their superiors.

In other words, by signing off on the NSA's extreme secrecy and resisting oversight from Congress and the courts, Obama was depriving himself of an essential managerial tool. He was reducing his own ability to monitor and deter misconduct by his subordinates. And so it's possible that one of the people who was most surprised by this week's disclosures was the president himself.