Historians like to play a parlor game called periodization, in which they attempt to define an era, often by identifying it with the individual who most shaped the times: the Age of Jackson, the Age of Reagan. Usually, this exercise requires many decades of hindsight, but not so in the 21st century.

In an interview broadcast on Monday, President Vladimir Putin said U.S. companies stood to profit in Russia, but suggested a Ukraine peace deal was still far off.