Ethiopia's federal armed forces are advancing on Tigray region in the north of the country. Tigray may be smaller but it has many battle-hardened warriors. What will happen next? Why was PM Abiy awarded the Nobel Peace prize in 2019? And is Eritrea helping Abiy to defeat the Tigrayans? And what about the tens of thousands of refugees heading to Sudan? Nexus speaks to William Davison from International Crisis Group, Horn of Africa analyst Awol Allo and Dana Hughes from the UN refugee agency UNHCR.