Another flare up underway as Ukraine-Russia tensions mount

Aired: 6/4/2015 | 0:05:49 | Clip
Ukrainian President Petro Poroshenko told his military to prepare for a possible "full scale" invasion from Russia. That warning came a day after fighting resumed in Eastern Ukraine, with casualties of 25 dead and dozens more injured. Gwen Ifill talks to David Herszenhorn of The New York Times about the ongoing tensions and failed cease-fire.