Back in the bad old days of the Cold War — when mutual nuclear annihilation was a policy option — a culture of secrecy arose in Washington. What wise observers understood even then was that while governments tried to keep secrets from each other, their chief concern was to keep secrets from their own people.

Considering what had been done in the name of the United States, from Mafia assassination plots against foreign leaders to murder, corruption and coups d’état, that concern was quite sensible. And there was hell to pay when the hidden history began to emerge.

During the nine years since 9/11 the national security state has doubled or tripled in size, with huge annexes in the private sector — and the culture of secrecy has metastasized simultaneously. As The Washington Post reports in a landmark series titled “Top Secret America,” by Dana Priest and William Arkin, the dimensions of the security colossus are stunning. It is nothing less than a fourth branch of government, so large, so powerful and so wealthy that no other branch can even grasp it, let alone control it.

How big? Nobody knows exactly, not even the Post investigative team, after two years of research that gathered many thousands of public records, including government contracts, intelligence reports and corporate documents, and included interviews with exceptionally knowledgeable sources.

But Priest and Arkin, whose work ought to be read by everyone, say that there are as many as 1,271 government entities and 1,931 private companies “working on programs related to counterterrorism, homeland security and intelligence in about 10,000 locations across the United States,” with an estimated 854,000 people — far more than live in the city of Washington, D.C. — holding top-secret security clearances.”

More than 30 building complexes for top-secret intelligence outfits are either under construction now or have been built since September 2001; altogether, these buildings occupy 17 million square feet of space.

Nobody in the White House, the Congress or any of the intelligence agencies, including the new Office of the Director of National Intelligence, seems to have the capacity to manage the complex tangle of agencies, companies and off-the-books entities that are supposed to protect us from violent extremism.

After reviewing the way that the Defense Department oversees its most sensitive intelligence and operational programs last year, retired Army Lt. Gen. John R. Vines told the Post reporters that he found the morass almost incomprehensible: “I’m not aware of any agency with the authority, responsibility or a process in place to coordinate all these interagency and commercial activities. The complexity of this system defies description.”

Calling this thing a “system” is a bit misleading. But does the leviathan offspring of government and corporation make us safer? That, too, is difficult to determine — in fact, it is impossible to determine, as the writers explain, because with “so many employees, units and organizations, the lines of responsibility began to blur.”

We have no way of knowing precisely what the national security complex does with the hundreds of billions of dollars in its shrouded budgets. What we do know is that billions of dollars are wasted through redundancy, corruption and sheer overgrowth. Too many agencies are performing the same tasks, such as shutting down terrorist money transfers and generating too many reports for anyone to read.

Most disturbing is that so many critical functions are outsourced to private corporations, primarily loyal to shareholders and management. The role of these corporations and their lobbyists, who controlled the creation of the Department of Homeland Security during the George W. Bush administration, is a challenge to democracy of unprecedented proportions.

But despite presidential promises of transparency, the Barack Obama administration is fostering more secrecy, not less — which is exactly the wrong way to cope with this problem. Our democracy and our security both depend on bringing this monstrous bureaucracy to heel — and that can only be done in the sunlight.

Joe Conason writes for The New York Observer.