MOSCOW (AP) -- Since he took over Crimea, President Vladimir Putin has seen his popularity soar and his opposition fall silent. So when the U.S. vice president told Russia to defuse tensions in Ukraine, Putin had few reasons to listen.
Emboldened by the national euphoria over the annexation of Crimea, Putin has moved against the few remaining critical voices in Russia and further neutered the news media. On Tuesday, a court cleared the way for sending his most vocal critic to prison.
Opposition leader Alexei Navalny was found guilty of slandering a lawmaker and fined the equivalent of $8,400. As a result, he may be jailed during a trial in a second case that starts Thursday. If found guilty, he could be sent to prison.
Navalny was nearly jailed last summer, when he was running a high-profile mayoral campaign in Moscow, but his conviction brought thousands into the streets in protest. The Kremlin evidently calculated it would be better to allow him to run for mayor, but he surprised everyone by finishing a strong second with 27 percent of the vote.
But now Putin, with his approval rating at 80 percent, no longer appears willing to tolerate any criticism.
Chillingly, Putin has begun to cast his critics as "national traitors," an intimation that anyone who opposes the Kremlin is serving the interests of the West. He has compared Russians who oppose his aggressive actions in Ukraine to the Bolsheviks, who took advantage of Russia's defeat in World War I to stage their 1917 revolution.
Navalny, who for years has led a relentless effort to expose government corruption, wrote an opinion column for The New York Times last month that urged the U.S. to impose sanctions on Putin's closest friends as punishment for the takeover of Crimea. The next day, five of the nine people Navalny mentioned were hit.
He understood that the Kremlin would make him pay for taking delight in the sanctions. "Time to pack a bag for jail," said a post on his Twitter feed.
The travel bans and asset freezes imposed on Russian officials by the U.S. and European Union have been greeted publicly by bravado and ridicule in Moscow, with those targeted proclaiming themselves proud to have made the sanctions list. But the sanctions have hurt Russia's economy by spooking investors and driving up inflation as the ruble has lost value.
The U.S. and EU have said they will broaden the list and impose more punishment against Russia's banking and energy sectors if Moscow fails to follow through on the provisions of an international agreement on Ukraine reached last week in Geneva.
U.S. Vice President Joe Biden said Russia must quickly "stop talking and start acting" to reduce tensions in Ukraine if it wants to avoid more sanctions. "We will not allow this to become an open-ended process," he said Tuesday in Kiev, the Ukrainian capital.
The visit was a show of U.S. support for Ukraine's interim government, which took over after the pro-Moscow president was ousted in February following months of protests and is struggling to hold the country together.
After Moscow seized Crimea, pro-Russian militias began taking over government buildings throughout southeastern Ukraine and setting up checkpoints on roads. Russia also has tens of thousands of troops arrayed along its side of the border.
Biden urged Moscow to encourage the pro-Russia forces to stand down and "address their grievances politically."
The threat of violence only increased, however. Ukraine's acting president reported late Tuesday that the bodies of two people he said were abducted by pro-Russia insurgents were found and a military aircraft was reportedly hit by gunfire. Acting President Oleksandr Turchynov ordered security forces to resume "anti-terror" operations in the east, although previous ones have had little effect.
Russia has denied that it has been stoking the turmoil or has failed to live up to the Geneva agreement.
Putin has little interest in seeing an easing of tensions in eastern Ukraine, which he has described as historically Russian lands and part of what he calls the "Russian world."
The government in Kiev and many in the West believe that provoking a confrontation would give Russia a pretext to invade. Putin has said he hopes he won't have to send in troops but retains the right to do so if necessary to protect ethnic Russians, a sizeable minority in Ukraine's east.
Putin's ultimate goal is to prevent Ukraine from moving closer to the European Union and NATO. How he intends to do this is still an open question.
But with dissenting voices at home falling silent, Putin may only need to see how far the West is willing to go.
EDITOR'S NOTE -- Lynn Berry, news editor of The Associated Press bureau in Moscow, has covered Russia since 1995.
Associated Press writers Nataliya Vasilyeva in Moscow and Nedra Pickler in Kiev, Ukraine, contributed to this report.