Through the fog of Twitter, it’s difficult to discern the precise details of what’s been happening in Ferguson, Mo., in the 10 days of protests spurred by the police killing of an unarmed teenager.

Still, maybe it’s not too early to wonder: When, exactly, did the United States become a banana republic?

“Why armored vehicles in a Midwestern inner suburb?” asks my Cato Institute colleague Walter Olson. What could possibly justify police “red-dotting” peaceful protesters with laser sights, or an attempted head-shot, with a tear gas canister, at a man standing in his own yard, insisting, “this [is] my property!”? Here you can watch police fumigate a news crew and take down their cameras — then chase off the other journalists filming the assault.

The Ferguson clampdown has even law and order conservatives like Red State’s Erick Erickson worried about “the militarization of the police and overkill by local police forces.” But maybe they’re not worried enough.

Last week, I found myself musing darkly, “Just wait till Ferguson’s cops get federally funded drones.” If you think paramilitary policing looks dystopian now, just wait till you see what’s being cooked up in defense contractors’ labs.

For decades now, as Radley Balko makes clear in his indispensable 2013 book, Rise of the Warrior Cop, federal subsidies have encouraged the proliferation of military ordnance on the home front — from M‑16s to grenade launchers to 30-ton armored vehicles. Since 2002, the Department of Homeland Security has accelerated police paramilitarization with more than $7 billion in Urban Areas Security Initiative grants.

With Homeland Security funding, “Police departments are arming themselves with military assets often reserved for war zones,” Sen. Tom Coburn, R‑Okla., noted in a 2012 report on the UASI program. Among those assets are surveillance drones and the Long Range Acoustic Device — a sound cannon deployed last week in Ferguson that can disperse crowds with a 149-decibel assault (permanent hearing loss begins at 130).

A Homeland Security report obtained by the Electronic Frontier Foundation in 2013 revealed that the agency has considered outfitting its expanding inventory of drones with “non-lethal weapons designed to immobilize” targets of interest.

Meanwhile, both Homeland Security and the Pentagon maintain a keen interest in developing crowd-control weapons for occupations at home and abroad. In 2007, the department’s science and technology arm “contracted for the development of the ‘LED Incapacitator,’ a nauseating strobe” weapon meant to overwhelm and disorient targets with rapid, random pulses of light.

Some have called it the “puke saber,” but the final product won’t necessarily be handheld. As the department noted in a cutesy blogpost entitled “Enough to Make You Sick,” “output and size can easily be scaled up to fit the need; immobilizing a mob, for instance, might call for a wide-angle ‘bazooka’ version.”

Then there’s the Pentagon’s “Active Denial System,” colloquially known as the “pain ray.” It’s a truck-mounted millimeter wave gun designed to create “an unbearable burning sensation” in anyone it’s aimed at.

Just imagine what a “puke cannon” or a “pain ray” could do to a crowd of looters — or a crew of pesky journalists. In time, and with the help of federal subsidies, we may graduate from banana republic to a science-fiction dystopia straight from the fevered brain of Philip K. Dick.

As James Madison warned at the Constitutional Convention in Philadelphia, “The means of defence agst. foreign danger, have been always the instruments of tyranny at home.”

It’s no accident that technology developed for population control in foreign counterinsurgencies is being turned inward — in fact, it’s been a matter of deliberate federal policy. But it’s not too late to reverse the slide.