Revelations of the sweeping collection of data on Americans by the National Security Agency (NSA) require that Congress launch a grand inquest into the post-9/11 national security state. Special committees in both the House and the Senate, armed with subpoena power, should investigate the scope of activities, the legal basis claimed, the operational structure and the abuses and excesses with a public weighing of costs and benefits.

The “war on terrorism” has gone on for 12 years, and while President Obama says it must end sometime, there is no end in sight. Secret bureaucracies armed with secret powers and emboldened by the claim of defending the nation have proliferated and expanded. The surprise of legislators at the scope of NSA surveillance shows that checks and balances have broken down.

We now know that the NSA, apparently acting under the secret orders of the court established by the Foreign Intelligence Surveillance Act (FISA), amassed phone records of and private information about Americans, drawing data from phone companies. These records admittedly give the NSA the ability to track the associations and the activities of anyone whom the agency chooses to target.

The president says he welcomes a “robust debate” on these activities, but then dismisses “the hype that we’ve been hearing,” asking Americans for trust, promising that “nobody is listening to your telephone calls.” Meanwhile, the administration and intelligence complex have mobilized to reassert the veil of secrecy. NSA Director Keith Alexander says “grave harm has already been done by opening this up.”

The commentariat has largely accepted the intelligence agency’s claims while fulminating against the crimes, even “treason,” of Edward Snowden, the contract employee who released the documents. Polls suggest Americans are uneasy but accepting if this surveillance is needed to defend the country from terrorist acts.

Trust them? Before the revelations, when James Clapper, the director of national intelligence, was asked by Sen. Ron Wyden (D-Ore.) in a Senate Intelligence Committee hearing if the U.S. government was collecting data on large numbers of Americans, he responded “No sir . . . . Not wittingly.” Asked later whether that was a lie, he said he responded in the “least untruthful manner.” Incredibly, his resignation is not yet on the president’s desk.

We cannot accept a paternal pat on the head, with Americans and Congress told to leave this to the professionals. At stake is the very heart of the Constitution and the democracy.

Our constitutional order is premised on limiting government intrusion to protect liberty. Citizens are guaranteed a sphere of privacy and the right of free speech and free association. The state can intrude on that space only if it has probable cause to believe a crime has been committed — and only when the evidence of that cause is reviewed by an independent magistrate. The state is also supposed to be transparent: its budgets made public, its expenditures and activities investigated by Congress and held publicly accountable.

The national security state — particularly in this age of an unending “war” on terrorists in every corner of the world — inverts that premise. It is built on an authoritarian assumption. In the name of security, it claims the right to investigate citizens, monitor their activities and know their secrets. On the other hand, the state’s activities, capacities, budgets and even legal authority are secret, closed from public review. To the extent that Congress provides oversight, it is limited to selected legislators who are sworn to uphold the curtain of secrecy even from their colleagues. Their concerns may be expressed only to officials, not to the people.

We have every reason to be suspicious. In the 1970s, shocking revelations led to the Church and Pike committee investigations that revealed stunning misdeeds: assassination plots, illegal mail opening, massive military spying, the FBI’s Cointelpro program. Congress responded with reforms — creating the intelligence committees and the FISA court, passing the War Powers Act, limiting covert action, strengthening the Freedom of Information Act and more.

At the time, as now, there were claims that the revelations were endangering lives and eroding our national security. That was nonsense then and is now. Sen. Jon Tester is clearly right in saying that Snowden’s revelations have served our democracy, not compromised our security. The question is not what to do about Snowden, but about the post-9/11 excesses he exposed.

The attempts to reform the national security state in the mid-’70s offer cautions for today’s debate. Too many of the reforms served to legitimate activities rather than eliminate them. The secret FISA court, for example, has provided less a curb than a blank check for intelligence agency surveillance. If the agencies are to be called to account, Congress must look to draw sharp limits.

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