A view of the Russian Federal Security Services on Lubyanka Square in Moscow in 2013. Journalists, dissidents and human rights workers say they are often followed or harassed by the Russian spy service. Ivan Sekretarev/AP hide caption

A cyclist looks at the flowers and messages placed along the beach for victims of the recent terrorist attack in Nice, France, on Wednesday. The recent spate of attacks around the world has raised questions about the limits of counterterrorism. Claude Paris/AP hide caption

Vyacheslav Trubnikov (right) was head of the Foreign Intelligence Service, Russia's equivalent of the CIA, from 1996 to 2000. He's shown here speaking with U.S. Deputy Secretary of State Richard Armitage in 2001 in Moscow. Trubnikov was Russia's deputy foreign minister at the time. Alexander Zemlianichenko/AP hide caption

At the height of the Cold War, the FBI and the National Security Agency built a secret tunnel beneath the Russian Embassy (shown here in 2013), so that American spies could eavesdrop on what was happening inside. J. Scott Applewhite/AP hide caption