“It went against the wind,” Mr. Karaganov said. “At this juncture, we just need to see whether he follows up on it.”

Image TV sets in a Moscow store showed President Dmitri A. Medvedevs speech on Wednesday, in which he spoke of liberalization. Credit... Natalia Kolesnikova/Agence France-Presse — Getty Images

As the speech approached, Mr. Medvedev faced intense pressure to calm nerves in Russia, crippled this fall by capital flight, a plunge in the stock market and a precipitous drop in oil prices. Mr. Putin typically gave the speech in the spring, using it to announce crowd-pleasing investments in infrastructure projects and social welfare programs.

Mr. Medvedev, by contrast, had to address the two shocks that had befallen Russia since he became president, the financial crisis and the war in Georgia, while combating the impression that Mr. Putin retained control over major decisions.

The speech he gave Wednesday, originally planned for Oct. 23, gave scant information about the government’s economic strategy going forward. It did, however, squarely lay blame for Russia’s troubles on the United States.

Mr. Medvedev said that American regulators had inflated a financial bubble and that the ensuing collapse “carried in its downfall to the trajectory of recession all financial markets of the planet.” He also said Washington had started the war in Georgia, saying, “Tskhinvali’s tragedy is, among other things, the result of the arrogant course of the U.S. administration, which hates criticism and prefers unilateral decisions.”

But it was the planned missile deployment, a possible early foreign policy test for Mr. Obama, that captured attention in the West on Wednesday.

Mr. Medvedev described specific measures Moscow would take if Washington went ahead with a plan to station a missile defense system in Poland and the Czech Republic. He said Russia would post mobile Iskander missiles — tactical weapons designed for use against targets like long-range artillery and airfields, in addition to missile defense systems — around Kaliningrad, an enclave at Russia’s western border. He also said Russia would use radio equipment to jam the Western missile defense system.