HAS VLADIMIR Putin lost touch with reality, as German Chancellor Angela Merkel reportedly suggested to President Obama? We don’t have access to his psychologist, but Mr. Putin’s rambling performance at a hastily arranged news conference Tuesday did support one disturbing observation: The Russian ruler’s speech has become indistinguishable from the propaganda of his state television network.

For the past few days, Russian television has been claiming that “fascists” and other armed extremists violently seized power in Ukraine, that they launched a campaign against Russian speakers and that “local defense forces” — not Russian troops — had stepped up to defend them in Crimea. That is pretty much what Mr. Putin offered journalists Tuesday, adding in a wild assortment of claims, many of them demonstrably false.

Though Ukrainian and U.S. officials say thousands of Russian troops have entered Crimea since Friday, Mr. Putin insisted he had not yet ordered the invasion approved by the rubber-stamp Federation Council. “If I do decide to use the armed forces,” he added, “this will be a legitimate decision in full compliance with international law, since we have the appeal of the legitimate president.” Never mind that Viktor Yanukovych, the fugitive leader Mr. Putin referred to, has not been seen since a news conference Friday in which he said he opposed Russian military intervention.

Mr. Putin’s bizarre performance vividly demonstrated how the political system he has created has insulated him from the truth about events both abroad and at home. He might imagine, for example, that the vast majority of Russians support his Ukraine ad­ven­ture; after all, the only discussion preceding the unanimous Federation Council vote was interrupted by a deputy who chastised his colleagues for “wasting the president’s time.” Yet a poll conducted by the Russian Public Opinion Research Center, an official institution, showed more than 73 percent of Russians opposing intervention.

Even a few years ago, Mr. Putin’s move would have provoked a public debate in Russia. Two leading opposition political parties have announced their objections, with one calling Mr. Putin’s actions “reckless” and the other saying they violate the right of Ukrainians to decide their own fate. But there is no debate in Moscow, because the leaders of those two parties, Boris Nemtsov and Alexei Navalny, have been arrested, while media that used to broadcast their views have been silenced. Antiwar demonstrations in Moscow were broken up by police, who arrested the participants.

The steep plunge Monday of the ruble, which cannot be wiped away by censors, did seem to remind Mr. Putin that Russia is vulnerable to economic damage in a world “where everything is interconnected and interdependent.” That’s why it is essential that the United States and the European Union move quickly to compound the financial costs of the invasion. Even if E.U. leaders are hesitant, President Obama and Congress should freeze the assets of top Russian officials and target Russian banks for exclusion from the U.S. financial system. That could provide the wake-up call that Mr. Putin desperately needs.