JUDY WOODRUFF:

We return to our week-long series, Inside Putin's Russia.

For years, the Kremlin and the media it controls have waged a multifaceted information and disinformation campaign both inside Russia, and pointed at its perceived adversaries. And last year, that effort crescendoed here during the U.S. presidential campaign.

Tonight, we look at the information war.

With the help of the Pulitzer Center on Crisis Reporting, special correspondent Nick Schifrin and producer Zach Fannin begin their report in Moscow.