When former White House national security aide Fiona Hill and diplomat David Holmes testified Thursday morning, they might not have made Donald Trump’s impeachment and conviction more likely, in the sense of providing new evidence of crimes and misdemeanors the president committed.

What they did do, however, was demonstrate that Trump and portions of the Republican Party have become what in the Cold War we used to call “useful idiots,” people who had become tools of the Kremlin not because they were devoted to the Soviet cause but because they were too stupid to realize how they were being manipulated.

In her opening statement, Hill put her finger on the problem:

Based on questions and statements I have heard, some of you on this committee appear to believe that Russia and its security services did not conduct a campaign against our country — and that perhaps, somehow, for some reason, Ukraine did. This is a fictional narrative that has been perpetrated and propagated by the Russian security services themselves.

Later, Hill was asked by the Democrats’ counsel, “Isn’t it also true that some of President Trump’s most senior advisers had informed him that this theory of Ukraine interference in the 2016 election was false?”

“That’s correct,” she replied. Instead, Trump chose to listen not to intelligence and national security officials but to his personal lawyer Rudy Giuliani, who was obsessed with the idea that it was not Russia but Ukraine that interfered in the 2016 election.

As this conspiracy theory has it, Ukraine, not Russia, hacked Democratic emails and set up Russia to take the fall for sabotaging the election, and a cybersecurity company called CrowdStrike helped cover it up. Trump pressed Ukrainian President Volodymyr Zelensky to help him make this true by finding an allegedly missing server in Ukraine.

This theory is not just bonkers, it is designed to serve the interests of the Kremlin. Holmes explained what Russia gains from the spread of the theory:

First of all, to deflect from the allegations of Russian interference. Second of all, to drive a wedge between the United States and Ukraine, which Russia wants to essentially get back into its sphere of influence. Thirdly, to besmirch Ukraine and its political leadership, to degrade and erode support for Ukraine from other key partners in Europe and elsewhere.

Indeed, just this week, at an economic forum in Moscow, Vladimir Putin celebrated the continued repetition of the Ukraine interference theory. “Thank God,” he said, “no one is accusing us of interfering in the U.S. elections anymore; now they’re accusing Ukraine.”

To be clear, Republicans are not spreading this theory because they want to serve Putin. They’re doing it because they want to serve Trump, who plainly believes that any discussion of Russian interference serves to delegitimize his election. As Hill said, Russian and Republican efforts to blame Ukraine for 2016 interference may have developed independently, but “those two things have, over time, started to fuse together.”

But as Hill testified, Russia wasn’t just trying to help Trump, it was attacking the entire system of democracy by delegitimizing the presidency:

The goal of the Russians was really to put whoever became the president, by trying to tip their hands on one side of the scale, under a cloud. So if secretary, former first lady, former senator Clinton had been elected as president, as indeed many expected in the run-up to the election in 2016, she too would have had major questions about her legitimacy. And I think that what we’re seeing here as a result of all these narratives, this is exactly what the Russian government was hoping for.

Furthermore, the effort to deflect attention away from Russia and on to Ukraine has the effect of making Russia’s almost inevitable effort to meddle in the 2020 election more likely to succeed. When it happens — and it will happen — how are Republicans going to react? It’s all a hoax, they’ll say. Just a Democratic attempt to delegitimize Trump, the way they did before. Nothing to see here, move along.

And Putin will marvel yet again at how easy it is to manipulate the useful idiots in the GOP into doing exactly what he wants.

Read more: