Can U.S. balance deterrence and diplomacy in responding to Russia’s move in Ukraine?

Summary: Days before Crimea’s planned referendum on whether to split from Ukraine, the White House made a symbolic gesture by hosting that country’s interim leader. How far should the U.S. go in supporting Ukraine’s new government? Hari Sreenivasan gets two views from Adrian Karatnycky of the Atlantic Council and Stephen Walt of Harvard University.