In December 2011, Alexei Navalny, a Russian blogger adept at exposing official corruption, helped organize a series of demonstrations that rocked the Kremlin following rigged parliamentary elections intended to set the stage for a new presidential mandate for Vladi­mir Putin. Once Mr. Putin was installed in office a few months later, he embarked on a sweeping and systematic campaign to crush the opposition movement and its leaders. The culmination of the largest crackdown in Russia since the collapse of the Soviet Union came Thursday, when a court in the city of Kirov sentenced Mr. Navalny to five years in prison.

In a cynical twist that has become a Putin signature, an activist known for his exposure of the illicit wealth of top officials was himself prosecuted on a charge of embezzlement. The case, involving timber sales, was not just phony but flamboyantly so — leaving no room for Russians to doubt why Mr. Navalny is being punished. In a final bit of stage management, the country’s newest political prisoner was released Friday pending an appeal; as The Post’s Will Englund reported, the regime hopes this will allow Mr. Navalny to compete in, and lose, an election for Moscow mayor before he is packed off to Siberia. Thus hopes Mr. Putin to complete the discrediting of a populist who dared to challenge what he called “the party of crooks and thieves.”

The Kremlin’s plan is unlikely to succeed. Mr. Navalny, a gifted public speaker and master of social media, offers Russia’s rising middle class everything that Mr. Putin, a blunt former KGB spy, lacks. The blogger’s anti-corruption crusade strikes at the heart of Mr. Putin’s regime, which is based on the massive theft of state revenue and resources. As wise Russians such as the analysts of Carnegie’s Moscow Center have been pointing out, it’s an unsustainable system, and Mr. Putin’s resort to repression is more likely to hasten than delay its collapse.

Unfortunately, President Obama has repeatedly misread Mr. Putin, judging him to be a strong and stable ruler with whom deals can be cut. In the hope of striking those bargains, Mr. Obama has chosen to disregard the regime’s brutal response to any challenge as well as its crude anti-Americanism. The administration’s silence on Russian human rights verges on the historic: Not since the Second World War has a president been so reluctant to speak out about political prisoners in Russia. The White House reaction to Mr. Navalny’s conviction was typical. Delivered not by Mr. Obama but by spokesman Jay Carney, it described the administration as “deeply disappointed and concerned” by a proceeding that many compared to the Stalinist show trials of the 1930s.

Mr. Carney has been hinting that Mr. Obama may cancel a meeting in Moscow with Mr. Putin scheduled for September, in what looks like an attempt to leverage Moscow’s cooperation on fugitive NSA leaker Edward Snowden. Mr. Obama should indeed call off the meeting — but he should do so explicitly to protest Mr. Putin’s assault on Russian civil society, and as the start of a policy that recognizes the regime for what it is.