Ukraine war: Nato watches Russian 'Zombies' in Estonia

In a cramped crew room, in a building just next to the runway of the Amari airbase in Estonia, the television is showing old episodes of Friends.

Feet up on the table, coffee mugs in hand, a bit of casual banter crisscrosses the room. On the TV screen, Rachel is just back from the hairdressers, Ross is upset about something. Then an airman pops his head around the doorway and announces calmly: "Zombie heading north out of Kaliningrad."

Instantly people are on their feet and moving next door to the Operations Room, where screens and digital maps marked "Nato Secret" flicker with streams of incoming data.

This is the Quick Reaction Force for Operation Azotize, Nato's Baltic Air Policing mission that guards the alliance's north-east borders where Russian aircraft regularly probe the boundaries of Nato territory.