In early July 2016, amid an outpouring of grief and anger over the police shooting of Philando Castile in the Twin Cities, an unknown organization called “Don’t Shoot” used Facebook to invite demonstrators to a protest. But something was very wrong.

The demonstration was set for the wrong police department, and all of the well-known local groups listed in the announcement disavowed involvement. Eventually, concerned local activists took over the event. It was only much later that they learned “Don’t Shoot” was likely a front for a “Russia-linked” organization that was using Facebook to sow discord across the United States.

These events would have been less surprising had the activists known about the prior century of Soviet and Russian influence campaigns directed against the United States and its allies, which is laid out in crisp detail in “Active Measures: The Secret History of Disinformation and Political Warfare,” by Johns Hopkins University professor and cyberwar expert Thomas Rid.

Rid, who testified before the Senate Select Committee on Intelligence in 2017 on disinformation operations, recounts elaborate and sometimes shocking tactics used to disinform democratic societies and inflame passions. “The goal of disinformation is to engineer division by putting emotion over analysis, division over unity, conflict over consensus, the particular over the universal,” Rid writes. And it is nothing new.

In the 1950s and 1960s, the KGB distributed fake letters intended to look like racist American KKK literature, and clandestinely directed the vandalism of synagogues and Jewish headstones in New York to make neo-Nazism appear as a rising threat, the book says, citing the accounts of Soviet-bloc defectors. Yet the same agents distributed accurate information on racism in America, to antagonize the KKK’s opponents.

KGB agents “weren’t simply posing as the KKK — remarkably, the same Russian operators posed as an African-American organization agitating against the KKK,” Rid writes.

The United States’ Central Intelligence Agency used its own “active measures” to disinform enemies. In the 1950s, a long-running CIA project published everything from forged pamphlets to glossy gossip and jazz magazines woven with disinformation to weaken “Communist manifestations” in East Germany.

But the U.S. eventually ramped down its disinformation efforts, while the Soviet efforts escalated.

In 1978, Soviet officials working through a major KGB front organization called the World Peace Council organized a symposium with an official U.N. agency to inflame European fear and anger over the U.S. plans to deploy neutron weapons, which could vaporize humans without damaging buildings. A peace demonstration with more than 40,000 legitimate peace activists soon overtook Amsterdam, and President Jimmy Carter postponed and eventually shelved plans for the weapon.

“Active Measures” has much to say about the shadowy internet influence campaigns that followed the rise of Vladimir Putin from KGB intelligence officer to Russian president, though attributing the source of internet activity is always tricky. Ultimately, Rid concludes that Russian and Russia-linked efforts to fill the internet with disinformation most likely did not cause many people to change their minds in 2016.

Rid is more concerned about a different species of online political warfare — the highly effective “hack and leak” method of prying loose actual secrets and leaking them online, as a group called the Shadow Brokers did with the National Security Agency’s hacking tools in 2016, to devastating effect. Sometimes real documents are leaked, and other times they’re doctored with forged material first.

Either way, if the goal is to engineer division by putting emotion over analysis and conflict over consensus, it’s hard to imagine a more efficient way of doing that than forcing all information to flow through ubiquitous screens that make it easy to obfuscate authorship and authenticity on a mass scale. Let’s be careful out there, everyone.

 Joe Carlson is a Star Tribune business reporter. 612-673-4779

 Active Measures
By: Thomas Rid.
Publisher: Farrar, Straus & Giroux, 528 pages, $30.