Corruption is at the center of the impeachment inquiry. Foreign-policy officials have testified that they worked to help Ukraine fight its entrenched corruption. The Democrats are alleging that President Donald Trump and his personal lawyer Rudy Giuliani, along with Giuliani’s two partner-helpers, Lev Parnas and Igor Fruman, tried to divert American foreign policy to their own corrupt ends, by instigating an investigation into ostensible corruption. Finally, the President’s defenders maintain that he had valid concerns about corruption in Ukraine, and therefore did nothing wrong.

In her testimony on Friday, Marie Yovanovitch, the former U.S. Ambassador to Ukraine, called corruption a challenge to Ukrainian democracy that was “equally important” to the challenge posed by Russian military aggression. Yovanovitch provided the historical and political context for Ukrainian corruption: she called it a “Soviet legacy” and reminded her audience that the Ukrainian Revolution of Dignity, in 2014, was essentially a revolt against corruption. Indeed, it was an act of obscene corruption that precipitated the revolution. In the fall of 2013, Ukraine was slated to sign a trade agreement with the European Union. But when the Russian President, Vladimir Putin, offered to buy fifteen billion dollars’ worth of Ukrainian government bonds and reduce gas prices, the Ukrainian President, Viktor Yanukovych, abruptly backed out of the European agreement, and the Ukrainian people took to the streets. It’s important to understand that Ukrainian revolutionaries, who went on to spend a long winter in Kiev’s central square, were not united in their desire to have a treaty with the European Union. What brought them together was their desire to have an accountable government and their outrage toward Yanukovich.

The problem with Yanukovich’s willingness to accept Russia’s generous aid was that he was acting not in the national interest but in his own: he stood to line his pockets—or gild his bathroom fixtures, as the case may be—by siphoning off a portion of every dollar that came from Putin. This is how corruption in post-Soviet states works. It does not look like lowly civil servants extracting bribes from citizens in exchange for services, although that happens, too. Instead, corruption looks like the people in charge using the instruments of government in order to accumulate wealth. Corruption is integral to the system.

In testimony during a closed-door impeachment hearing, Fiona Hill, a former National Security Council official in the Trump Administration, said that corruption posed a threat to democracies in post-Soviet states because many of them “weren’t particularly well set up to be independent countries, and there was a great deal of efforts by private interests to, you know, pick away at the structures of government.” But the Soviet system from which these states emerged was itself fundamentally corrupt. Being a part of the regime could make one better off than one’s fellow-citizens; at the top of the Party pyramid, one could become fantastically wealthy. Under totalitarianism, being a part of the regime was the only way to enrich oneself. The intellectual leader of perestroika, Alexander Yakovlev, used the word “mafia” to describe the functioning of the Soviet cabinet, in which each minister presided over his own clan and own profit-making chunk of the state. In the nineteen-nineties, this system morphed into the oligarchic structures that took root in Russia, Ukraine, Kazakhstan, and several other post-Soviet states.

But corruption is not only an integral feature of many post-Soviet power systems, it is also a powerful weapon in the hands of post-Soviet autocrats. Dozens of former civil servants, including governors and federal ministers, have been jailed on corruption charges in Russia. Accusations of corruption have been used to persecute the theatre director Kirill Serebrennikov (because his theatre received state funding) and even the anti-corruption activist Alexei Navalny (because he acted as an unpaid consultant to a governor at one point, and because he and his brother owned a company that allegedly undercut the national postal service). Because nothing works without corruption, every civil servant is always somehow outside the law—always vulnerable to accusations of corruption and therefore always either controllable or easy to eliminate. When everyone is implicated in corruption, the fight against corruption can be waged only selectively, and this subverts the possibility of the rule of law, thereby reinforcing the structure that rests on corruption.

Perhaps Trump intuited the potential of corruption-as-cudgel, or perhaps his lawyer’s associates suggested it. Either way, it was exactly the instrument that he was trying to use when he demanded that Ukraine launch a corruption investigation into Hunter Biden’s business dealings. In other words, Trump was deploying both edges of the corruption sword: he was using the power of his office to his personal political ends, and he was wielding the accusation of corruption in the way an autocrat wields it. When the Republicans on the House Intelligence Committee defend the President’s actions, by asserting that he was concerned about corruption in Ukraine, they become accomplices in his autocratic attempt.

We use the word “corruption” to describe abuses of power, especially those motivated by profit. We also use the word “corruption” to describe something that is transformed, corroded beyond recognition. When the word “corruption” is used by an evidently corrupt politician—such as our self-dealing, profit-seeking, mendacious President—to describe something that other people do, the word “corruption” itself becomes corrupted. But it is not only language that can be changed and turned into the opposite of what it originally means. The same can be done with foreign policy, and with government itself. This is the essence of the story that the impeachment inquiry is telling.