The recent Kerry-Lavrov initiative to end the conflict in Syria through talks was met with skepticism among those who believe that the United States and Russia will bring their own agendas to the table, that Bashar al-Assad will refuse to step down, and that the Syrian opposition is too fragmented to strike a deal. But those are common problems, and successful talks can be -- and have been -- started under just such conditions.

From wigs to dead drops, the espionage tussles between the United States and Russia are increasingly playing by the old Cold War rules -- including the public shaming of the unlucky spooks who get caught.

In his scholarship, Waltz asked the tough questions about the difficult and important issues. He was motivated by both theoretical and policy questions, the latter often setting the agenda for the former. He was intellectually courageous, usually staking out iconoclastic positions -- some of which were initially derided, many of which ended up becoming mainstream thinking. No matter what one’s theoretical persuasion, he was an intellectual force that had to be reckoned with.