MOSCOW — Westerners often see Russian politics in terms of a high-level struggle between liberals and conservatives: Ligachev and Yakovlev under Mikhail Gorbachev; reformers and nationalists under Boris Yeltsin; siloviki and economic liberals under Vladimir Putin.

Westerners also view Russia in terms of a tradition whereby every new czar partly repudiates the legacy of his predecessor, creating a political thaw at the beginning of a new reign. Nikita Khrushchev's de-Stalinization is Exhibit A.

Both methods were used to describe the Putin-Dmitri Medvedev relationship — to understand its nature and dynamic, and what it portends for Russia. But observers remain puzzled.