Robert Gates, the bridge between the Bush and Obama presidencies, is not very worried about Russia.  From the Washington Post:

A longtime Russia analyst during his years with the CIA, Gates today sees Moscow as less of a threat than do many inside and outside the U.S. military establishment. On PBS’s “Charlie Rose Show” Dec. 17, he spoke of the historical insecurity of Russian leaders, recalling how Prime Minister Nikita Khrushchev was embarrassed in Geneva in 1955 that President Dwight D. Eisenhower’s plane was bigger than his. “I mean, this is pretty deep-seated stuff, and so trying to avoid touching on one of Russia’s insecurities is almost impossible,” Gates concluded.

He cautions, in the January-February issue of Foreign Affairs, that before the United States starts to think it must rearm for another Cold War after Russia “crushed Georgia’s tiny military,” it must realize that Moscow is seeking to “exorcise past humiliation.” And although the Russian army has recently improved its conventional forces, it is “a shadow” of what it once was, he says, and “adverse demographic trends in Russia will likely keep those conventional forces in check.”