Putin, then Russia’s prime minister, greets Biden, then vice president, in Moscow in March 2011. Biden has said he once told Putin he looked into his eyes and didn’t see a soul.

Vice President of the United States Joe Biden, left, shakes hands with Russian Prime Minister Vladimir Putin in Moscow, Russia, Thursday, March 10, 2011. The talks in Moscow are expected to focus on missile defense cooperation and Russia’s efforts to join the World Trade Organization. (AP Photo/Alexander Zemlianichenko)