NATO accused Russia of violating Ukrainian sovereignty by sending equipment and combat troops into eastern Ukraine to support pro-Russian rebels. Russia denies this. In response, European leaders planned to meet Saturday to discuss the possibility of further sanctions. We'll discuss the latest developments in Ukraine.
NATO: Russia Violated Ukraine's Sovereignty
Michael McFaul, political scientist at Stanford University and former U.S ambassador to Russia
Edward W. Walker, professor of political science at UC Berkeley
David Stern, journalist with the BBC in Kiev, Ukraine