ITV News Correspondent Rupert Evelyn meets the British soldiers on the border with Ukraine as part of Nato's mission
Russia’s invasion of Ukraine has prompted a huge deployment on Nato's eastern flank. It is significant both for its scale and the security it provides to those countries bordering Russia.
Soldiers are having their tours extended, more military hardware arrives daily and the message to President Vladimir Putin is clear - Nato is defending the border between Russia and its member states and forces are on high alert for any incursion either in the air or on the ground.
We visited British Troops in Estonia. The total number has doubled recently - 2,000 soldiers, comprising two battlegroups, are now based in this Baltic nation. They are British but this is a Nato tasking and they are ready to respond if called upon.
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Usually Nato only has two nations deployed side-by-side here but for the first time soldiers from three countries, Britain, France and Denmark as well as their Estonian host are all working as one.
In the air, Belgium F16 fighters are combat ready and can be airborne within 15 minutes of being ordered into action. They are waiting on a decision to extend their presence in Estonia adding to the hardware available to Nato commanders.
Nato describes itself as a defensive alliance and right now they have ramped up their resources on a scale not seen for many years.