Nine years after the terrorist attacks of 2001, the United States is assembling a vast domestic intelligence apparatus to collect information about Americans, using the FBI, local police, state homeland security offices and military criminal investigators.

The system, by far the largest and most technologically sophisticated in the nation’s history, collects, stores and analyzes information about thousands of U.S. citizens and residents, many of whom have not been accused of any wrongdoing.

The government’s goal is to have every state and local law enforcement agency in the country feed information to Washington to buttress the work of the FBI, which is in charge of terrorism investigations in the United States.

Other democracies – Britain and Israel, to name two – are well acquainted with such domestic security measures. But for the United States, the sum of these new activities represents a new level of governmental scrutiny.

This localized intelligence apparatus is part of a larger Top Secret America created since the attacks. In July, The Washington Post described an alternative geography of the United States, one that has grown so large, unwieldy and secretive that no one knows how much money it costs, how many people it employs or how many programs exist within it.

Today’s story, along with related material on The Post’s Web site, examines how Top Secret America plays out at the local level. It describes a web of 4,058 federal, state and local organizations, each with its own counterterrorism responsibilities and jurisdictions. At least 935 of these organizations have been created since the 2001 attacks or became involved in counterterrorism for the first time after 9/11.

(Search our database for your state to find a detailed profile of counterterrorism efforts in your community.)

The months-long investigation, based on nearly 100 interviews and 1,000 documents, found that:

* Technologies and techniques honed for use on the battlefields of Iraq and Afghanistan have migrated into the hands of law enforcement agencies in America.

* The FBI is building a database with the names and certain personal information, such as employment history, of thousands of U.S. citizens and residents whom a local police officer or a fellow citizen believed to be acting suspiciously. It is accessible to an increasing number of local law enforcement and military criminal investigators, increasing concerns that it could somehow end up in the public domain.

* Seeking to learn more about Islam and terrorism, some law enforcement agencies have hired as trainers self-described experts whose extremist views on Islam and terrorism are considered inaccurate and counterproductive by the FBI and U.S. intelligence agencies.

* The Department of Homeland Security sends its state and local partners intelligence reports with little meaningful guidance, and state reports have sometimes inappropriately reported on lawful meetings.

Counterterrorism on Main Street In cities across Tennessee and across the nation local agencies are using sophisticated equipment and techniques to keep an eye out for terrorist threats — and to watch Americans in the process.Launch Gallery » The need to identify U.S.-born or naturalized citizens who are planning violent attacks is more urgent than ever, U.S. intelligence officials say. This month’s FBI sting operation involving a Baltimore construction worker whoallegedly planned to bomb a Maryland military recruiting station is the latest example. It followed a similar arrest of a Somali-born naturalized U.S. citizen allegedly seeking to detonate a bomb near a Christmas tree lighting ceremony in Portland, Ore. There have been nearly two dozen other cases just this year.

“The old view that ‘if we fight the terrorists abroad, we won’t have to fight them here’ is just that – the old view,” Homeland Security Secretary Janet Napolitano told police and firefighters recently.

The Obama administration heralds this local approach as a much-needed evolution in the way the country confronts terrorism.

Top Secret America is a project two years in the making that describes the huge security buildup in the United States after the Sept. 11, 2001, attacks. Today’s story is about those efforts at the local level, including law enforcement and homeland security agencies in every state and thousands of communities. View previous stories,explore relationships between government organizations and the types of work being done, and view top-secret geography on aninteractive map. However, just as at the federal level, the effectiveness of these programs, as well as their cost, is difficult to determine. The Department of Homeland Security, for example, does not know how much money it spends each year on what are known as state fusion centers, which bring together and analyze information from various agencies within a state.

The total cost of the localized system is also hard to gauge. The DHS has given $31 billion in grants since 2003 to state and local governments for homeland security and to improve their ability to find and protect against terrorists, including $3.8 billion in 2010. At least four other federal departments also contribute to local efforts. But the bulk of the spending every year comes from state and local budgets that are too disparately recorded to aggregate into an overall total.

The Post findings paint a picture of a country at a crossroads, where long-standing privacy principles are under challenge by these new efforts to keep the nation safe.

The public face of this pivotal effort is Napolitano, the former governor of Arizona, which years ago built one of the strongest state intelligence organizations outside of New York to try to stop illegal immigration and drug importation.

Napolitano has taken her “See Something, Say Something” campaign far beyond the traffic signs that ask drivers coming into the nation’s capital for “Terror Tips” and to “Report Suspicious Activity.”

She recently enlisted the help of Wal-Mart, Amtrak, major sports leagues, hotel chains and metro riders. In her speeches, she compares the undertaking to the Cold War fight against communists.

“This represents a shift for our country,” she told New York City police officers and firefighters on the eve of the 9/11 anniversary this fall. “In a sense, this harkens back to when we drew on the tradition of civil defense and preparedness that predated today’s concerns.”

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