“The F.B.I. launched an intrusive investigation of a U.S. presidential campaign on the thinnest of suspicions that, in my view, were insufficient to justify the steps taken,” he said.

Similarly, Mr. Barr’s response to the report from Robert Mueller on Russian interference and Mr. Trump’s purported presidential misconduct was to cast doubt on his own staff, questioning their work product as well as their ethics and legal reasoning. Even before he became attorney general, Mr. Barr questioned Mr. Mueller’s investigation of the president for obstruction of justice in a 19-page legal memo he volunteered to the administration.

And where he could have neutrally passed Mr. Mueller’s findings to Congress, he instead took the widely criticized and unusual step of making and announcing his own legal conclusions about Mr. Mueller’s obstruction inquiry. He followed up this Cohn-like behavior with testimony in the Senate, where he insinuated that the United States government spied on the Trump campaign. Mr. Barr apparently has decided that, like Cohn, he serves Donald Trump and not the Constitution or the United States, flouting his oath of office and corrupting the mission of the Justice Department.

In the past, the United States has, however imperfectly, advanced the rule of law and supported governments committed to an anti-corruption agenda. According to George Kent, a State Department official who testified in the House impeachment inquiry, Russia sees corruption as a tool to advance its interests. So when the United States fights a kleptocratic culture, it serves not only lofty humanitarian goals but also our national security. Mr. Zelensky ran a campaign and was elected on a platform that put fighting corruption at the forefront. He should have received extensive and unmitigated support in that effort.

In the former East Bloc countries, despite the hopes of many for a post-Soviet era where democracy would thrive, the parties and politicians in power have consolidated their control in a manner reminiscent of the Communist era.