Last spring, after Russia annexed Crimea and began intervening in eastern Ukraine, the United States and the European Union introduced sanctions against Russian individuals and businesses. But if sanctions are to be an effective tool in countering Vladimir Putin's ambitions — a topic of debate in the West — they must combine a firm hand toward Russia's president with an open one toward its people.

To understand the role that sanctions can play in managing the Kremlin, one need only consider the importance of money to its occupant.

From the beginning of the century until very recently, Russia was flooded with petrodollars; as the flow of money increased, so did Putin's audacity and aggression.