In his excellent testimony March 30 before the Senate intelligence committee, Thomas Rid, a professor in the Department of War Studies at King’s College London, explains how Russia has perfected the art of exploiting unwitting agents.

Unwitting agents are fools who are doing the bidding of another person or country without realizing it. Another term for them is “useful idiot,” a phrase supposedly used by Lenin to describe liberals and Social Democrats who helped advance the Communist cause outside the Soviet Union.

Rid said three different types of unwitting agents stand out from the chaos of the 2016 election:

Unwitting agent #1: Wikileaks.

The US intelligence community concluded with a high degree of confidence that Russia’s foreign military intelligence service, the GRU, was the source for the reams of stolen Clinton campaign emails published by Wikileaks.

Wikileaks has repeatedly denied that Russia was the source for the leaked DNC emails, which shows why an unwitting agent is so useful.

Wikileaks clings to the moral high ground because it believes it acted in the name of justice or goodness, not in the name of a Russian intelligence agency.

So when Wikileaks insists that the emails were leaked to them by an insider, it does so with considerable conviction that has taken others such as the influential Fox commentator Sean Hannity.

Unwitting Agent #2: Twitter

Twitter was hugely influential among opinion leaders in the 2016 election, foremost among them the Twitterer-in-chief, Donald Trump. But it’s very hard to tell what on Twitter is real and what is fake.

A recent study by computer scientists at Indiana University and USC tried to tackle the question of how many Twitter accounts are bots. These are automated and semi-automated software applications that mimic human behavior and can be used to drive grassroots political support, spread rumors, or bully opponents.

The researchers conclude that as many as 15 percent of all Twitter accounts are bots, and given the increasing sophistication of bots, this may be a conservative estimate. Twitter claims it has 313 million “active” monthly users. If the study is correct, 47 million Twitter users are not human.

Twitter for its part could easily inform the public how many of its accounts are bots, whether influential accounts during the 2016 election were human or not, or how many Twitter trends began overseas.

But it is not in the company’s interest to do so. The inflated numbers make it appear that Twitter has active users than its published numbers claim it has. Pulling back the curtain on bots would depress Twitter’s value as a publicly-traded company.

Unwitting Agent #3: Journalists

The Soviet Union excelled at planting stories. Operation INFEKTION planted the devastatingly rumor that AIDS had been created by US scientists seeking new and potent biological weapons that still echoes around the globe.

But planting these stories was hard work, as this CIA history shows. It took time to craft believable forgeries and build relationships with newspapers. A CIA study estimated that the Soviets spent $3 billion annually influencing world perceptions through its “active measures” campaigns.

That was then. Now, Rid says, it’s much easier:

Cold War disinformation was artisanal; today it is outsourced at least in part — outsourced to the victim itself. American journalists would dig deep into large dumps, sifting gems, mining news, boosting ops.

The hours and reams of newsprint that reporters devoted to hacked emails — with little thought to the who, what or why of their appearance — made American journalism an unwitting agent of Russian intelligence.

Unwitting Agent #4: Donald Trump

Trump is not part of Rid’s testimony, but I felt the need to add him. Donald Trump is the biggest unwitting agent of them all.

He has professed his love for Wikileaks and for Twitter, as well as for rumors that originate with Russia. He has allowed himself to used and manipulated by people with questionable motives.

In an op-ed in The New York Times, former acting CIA Director Michael Morrell summed it up this way:

President Vladimir V. Putin of Russia was a career intelligence officer, trained to identify vulnerabilities in an individual and to exploit them. That is exactly what he did early in the primaries. Mr. Putin played upon Mr. Trump’s vulnerabilities by complimenting him. He responded just as Mr. Putin had calculated.

Mr. Putin is a great leader, Mr. Trump says, ignoring that he has killed and jailed journalists and political opponents, has invaded two of his neighbors and is driving his economy to ruin. Mr. Trump has also taken policy positions consistent with Russian, not American, interests — endorsing Russian espionage against the United States, supporting Russia’s annexation of Crimea and giving a green light to a possible Russian invasion of the Baltic States.

In the intelligence business, we would say that Mr. Putin had recruited Mr. Trump as an unwitting agent of the Russian Federation.