Information is power. This is the logic — or at least the aspiration — behind the U.S. government’s current approach to intelligence gathering: the more data (or metadata) in hand, the more control. The National Security Agency’s surveillance leviathan, funded by a black budget and presided over by a star-chamber court, suctions up almost inconceivable amounts of material from around the world, including your phone and computer. How did this begin, and where will it end?

History shows us that this is a story about empire. For more than a century, major innovations in U.S. intelligence-collection capacity have accompanied major expansions of U.S. influence on the world stage. In some cases, U.S. government agencies used distant theaters to test approaches they would later deploy on the home front. Elsewhere, they helped foreign police build internal surveillance systems. The trainers then returned to work in domestic law enforcement, employing the same practices locally. Either way, U.S. residents should worry. The information-management strategies the U.S. has used in projecting its power abroad have usually come home to roost.

It was during the United States’s bloody occupation of the Philippines after the Spanish-American War that U.S. policymakers first yoked intelligence collection to imperial expansion and then repatriated it. As the historian Alfred W. McCoy writes in “Policing America’s Empire,” U.S. colonial police, powered by a nascent information revolution and unfettered by constitutional restrictions, built an elaborate covert surveillance apparatus to help quell resistance. Their system maintained individual file cards on an astonishing 70 percent of the local population.

When the U.S. scaled down the occupation during World War I, veterans of the counterinsurgency effort, including the military intelligence pioneer Ralph Van Deman, returned to lead a large-scale ramp-up of domestic surveillance infrastructure, designed to provide the enforcement muscle for new legislation such as the 1917 Espionage Act and the 1918 Sedition Act. Among Van Deman’s achievements: a collaboration between his military intelligence division and the American Protective League, a private network of 300,000 citizen spies that even after the war spent decades targeting German-Americans, repressing labor militancy, spying on civil rights activists and identifying Hollywood communists for blacklisting. (Van Deman also amassed a personal archive of file cards on a quarter-million suspected U.S. subversives.)

As fears about fascism and communism escalated during the 1930s, U.S. attentions turned outward again. Franklin Roosevelt’s administration, eager to access the intelligence collected by foreign police forces, directed the Federal Bureau of Investigation to develop relationships with its counterparts abroad. The FBI helped countries such as Brazil and Colombia set up secret intelligence services from which the U.S. could profit, both by gaining access to foreign surveillance data and by honing strategies that could later be integrated into domestic police practices.

As the Cold War set in and the Central Intelligence Agency and the NSA were established (in 1947 and 1952, respectively), the U.S. not only stepped up its own intelligence collecting capabilities but also trained police forces in Japan, Greece and Uruguay, among others, in anti-communist counterinsurgency methods. Best dramatized by Costa-Gavras in the film “State of Siege,” this proxy training aimed to build on-the-ground surveillance capacity, allowing local allies to share the work of Cold War containment and simultaneously guaranteeing the U.S. government access to the information their allies could now capture.

Take the case of Guatemala. There, soon after the CIA helped orchestrate the 1954 coup that ousted the democratically elected leftist President Jacobo Arbenz, U.S. trainers arrived to help the new military government consolidate power. Their first order of business, as one U.S. adviser reported back, was to help the Guatemalan police optimize its “almost neurotic hypersensitiveness to communist activity” by updating its “hopelessly inadequate” filing system. Simply put, to hunt down enemies of the state — to track their movements, record their political opinions, identify their associates, map their daily routes and, ultimately, eliminate them — you had to keep good files on them.

U.S. technicians ran daily classes in records management for Guatemalan agents, teaching them the latest information management methods and supervising the creation of a new records bureau. But that wasn’t all. U.S. agencies, most famously the State Department’s now defunct Office of Public Safety, provided filing cabinets for safe document storage, updated the Guatemalans’ dated fingerprinting system, oversaw a transition to the use of three-by-five file cards, compiled blacklists of “subversives” and beefed up the police’s special investigation squads. They also built a telecommunications center (connected to a Central America–wide system) that allowed the country’s various security forces to share intelligence with one another, with neighboring countries and, most important, U.S. officials in the Panama Canal Zone.

Guatemalans soon came to know that center, tellingly, as “the archive.” As the government’s counterinsurgency campaign heated up, the police used its new archival capabilities to murder and disappear tens of thousands of students, trade unionists and opposition politicians — a surgical strategy enabled by modern information technology. Arguably, the most lethal tools sent to Guatemala’s police by the United States were not guns, munitions or helicopters but file cards and filing cabinets.

At the same time, the U.S. trainers — back after stints in Guatemala, Vietnam, Colombia or the other countries where this template was used — adapted their expertise to domestic policing, either as private consultants or by integrating into metropolitan police forces in cities like Detroit and Chicago. According to historians Jeremy Kuzmarov and Stuart Schrader, practices developed by the Office of Public Safety at the peripheries of the U.S. empire were repurposed locally to pacify the social unrest of the 1960s and 1970s.

The FBI’s Cointelpro, a series of covert projects to spy on, infiltrate and discredit groups and individuals the FBI deemed suspect (including New Left and civil rights organizations), echoed the programs U.S. trainers had set up abroad. Strategies and tactics thus hopscotched across national borders and back, traveling anywhere the U.S. sought to increase its influence.

After 9/11 and the Afghanistan and Iraq invasions, the U.S.’s global intelligence-gathering system went into hyperdrive. In Afghanistan, U.S. forces have aimed to collect extensive biometric data on every single living Afghan for counterinsurgency purposes. Civil liberties watchdogs in the U.S., such as the Electronic Frontier Foundation and Public Intelligence, are concerned by how this emphasis on high-tech biometric collection has already taken root in domestic law enforcement. (Biometrics aren’t inherently problematic, but their use can present very real privacy threats, and they can easily be repurposed for state or corporate surveillance.)

Enabled by new technologies, a new modus operandi has emerged as well. As one former U.S. intelligence official explained, “rather than look for a single needle in the haystack” — scanning for information on particular cases of interest — the new strategy is now to “collect the whole haystack.” This began in earnest with the Real Time Regional Gateway program, implemented in Iraq and then in Afghanistan to vacuum up all possible information.

The ethos of RTRG appeared in the U.S. in the form of the PRISM data-mining program. Americans were scandalized to learn from former National Security Agency contractor turned whistle-blower Edward Snowden that the whole haystack included their phone calls and emails. They should understand that this will remain the case for as long as the U.S. is permitted to maintain its amorphous campaign against “terror,” the diffuse goals of which are now seen to require a blanket approach to information gathering.

Policing is, at its core, informational and archival in nature. High-octane data mining may have replaced the file card, but the underlying concept is the same. So long as the United States chooses to continue in its self-appointed role as global policeman, it will, necessarily, maintain what Snowden described before fleeing the country as a “massive surveillance machine” — nothing less than an archive of the world, the home front included.

Kirsten Weld is an assistant professor of history at Harvard University and the author of "Paper Cadavers: The Archives of Dictatorship in Guatemala."

Originally published by Al Jazeera America