US wants to draw China out, keep Russia in
The United States' abandonment of its "restarted" Russia policies and return to a policy of containment in the Ukraine crisis is not because of simple opportunism, it is based on its understanding of Russian diplomatic culture and the country's international position. It is such factors that have determined the major differences between the US policies toward Russia and China.
In 2005, Robert Zoellick, who was the US secretary of state at the time, made a typical elaboration of the differing US policies regarding Russia and China: "For 50 years, our policy was to fence in the Soviet Union while its own internal contradictions undermined it. For 30 years, our policy has been to draw out the People's Republic of China."
After the financial crisis, the US government considerably downgraded its evaluation of Russia's national strength and importance in international affairs. In an interview on July 24, 2009, during his visit to Ukraine, Vice-President Joe Biden said that Russia's population was shrinking, its economy withering, and its banking and financial sectors would not survive another 15 years. While on March 25 at the 2014 Nuclear Security Summit in The Hague, the Netherlands, US President Barack Obama stated that Russia is only a weak "regional power".