What's behind the new tensions in the Nagorno-Karabakh region?

Armenia and Azerbaijan are accusing each other of moving troops to their border areas. Tension has been rising in the disputed Nagorno-Karabakh region. But why is this a concern now? And what's the role of foreign powers? Join host Imran Khan. Guests: Farid Shafiyev - Chairman, Center of Analysis of International Relations. Anna Ohanyan - International Relations Professor, Stonehill College. Ben Aris - Editor-in-Chief, bne IntelliNews.