UK military personnel have maintained a rotating presence in Estonia since 2017, with troops taking on a leading role in NATO's response to a developing threat from neighbouring Russia.
Operation Cabrit sees about 800 to 950 British service members lead efforts to tighten Euro-Atlantic security alongside French, Danish and Estonian forces.
As 1st Battalion the Mercian Regiment prepares to take charge in March, Forces News explores the history and nature of the deployment, and what it represents to the NATO military alliance.
What Is Op Cabrit?
The deployment itself accounts for the British aspect of NATO's Enhanced Forward Presence (EHP) in Estonia, Lithuania, Latvia and Poland.
This includes leading one of four battlegroups (there is one for each of the four countries) in Estonia, increasing combat readiness as the threat from bordering Russia develops.
About 800 troops lead simulation exercises to prepare forces for a potential attack, as well as carrying out engagement with schools and local community members to talk about NATO, their role and the mission.
Op Cabrit also sees a smaller contingent of about 150 personnel deployed to Poland, where they are part of the US-led battlegroup.
When And Why Did Op Cabrit Begin?
NATO's Warsaw Summit in 2016 committed the alliance to a greater presence in three Baltic states and Poland, in light of a more assertive Russia in the same decade.
Regarding Russian aggression in the build-up to 2016, the Ministry of Defence (MOD) cites concern over a proven willingness to use military force against Georgia in 2008 and in 2014's annexation of Crimea.
NATO's founding document states that an attack on one member state is an attack on the entire alliance, and so four battalions in Estonia, Poland, Lithuania and Latvia became operational in 2017 – the latter led by Germany and Canada, respectively.
What Happens On Op Cabrit?
Allies train on a weekly basis, on exercises which vary in scale.
The annual Exercise Spring Storm sees Estonian forces take on the role of the very same foreign threat they are preparing to counter in reality.
On the exercise, British forces act as the defending force – mobilising in training grounds, towns and villages as if the fictional threat were advancing.
In previous years, about 1,000 UK personnel have joined thousands of multinational troops on the drill, about 15 kilometres from the Russian border.
Alongside this, Op Cabrit sees the troops enter the local towns in a different capacity – explaining the NATO presence to the local population.
WATCH: 1,000 British Personnel In Estonia's Exercise Spring Storm in 2019.
How Real Is The Threat?
Shortly before 2021, the threat from Russian forces was deemed "not imminent" by the MOD, but there are consistent examples of aggravation against NATO from beyond its eastern border.
Last year 150 RAF personnel returned from Operation Azotize in Lithuania, a Baltic Air Policing deployment to defend NATO air space.
During the summer mission, RAF Typhoons scrambled twice within 48 hours to intercept Russian aircraft.
In the same period, the Intelligence and Security Committee warned that the UK is one of Russia's "top Western intelligence targets" and that Russian influence in the UK is the “new normal”.
Later in 2020, the Chief of the Defence Staff, General Sir Nick Carter, condemned Russia for assembling warships and aircraft "from the northern Baltic and Black Sea fleets in a show of force in the waters off the British and Irish coasts".
He added that the country has been "flexing their muscles" in the UK's backyard in a manner not seen since the Cold War.
This sentiment was echoed by Defence Secretary Ben Wallace during a recent visit to Estonia over the winter period.
Nonetheless, when soldiers from 1st Battalion The Mercian Regiment deploy to the region next month, they will lead a combat-ready but defensive battlegroup.