SOFIA, Bulgaria — WHEN George Kennan wrote his famous “Long Telegram,” his 1946 letter to Secretary of State James F. Byrnes that laid the foundation for America’s containment policy against the Soviet Union, he mentioned Joseph Stalin just three times — despite the fact that, by then, the Russian leader ran his country like an emperor.

Seven decades on, Stalin’s current heir, Vladimir V. Putin, finds his name emblazoned on nearly every page of the myriad memos and papers struggling to understand the mind-set driving Russia’s strategic behavior. To understand Mr. Putin, the thinking goes, is to understand Russia. But is that quite right?

In the heady days of the Cold War, Americans tended to view Soviet decision making as a black box: You know what goes in, you know what comes out, but you are clueless about what is happening inside. Soviet policy was thus believed to be both enigmatic and strategic. There was little room for personality or personal philosophy; understanding the system was the only way.

According to Gleb Pavlovsky, Mr. Putin’s former spin doctor extraordinaire, these days the Kremlin is still enigmatic, but no longer strategic. For Mr. Pavlovsky, Kremlin policy is fashioned rather like the music of a jazz group; its continuing improvisation is an attempt to survive the latest crisis.