Ukraine crisis: British troops arrive in Estonia
2 May 2014 Last updated at 19:17 BST
Britain has joined with other NATO countries to provide extra security for Latvia, Estonia and Lithuania - all in response to the crisis in Ukraine.
The Baltic states, all close to Russia, have no fighter-aircraft and have for years been dependent on the alliance for protection.
Four RAF Typhoon fighters are part of a NATO force of 20 jets now guarding the Baltics.
A total of 100 British troops arrived in Estonia for a training exercise with that country's defence forces, along with the Defence Secretary Philip Hammond.
Jonathan Beale travelled with them.