Responsibility for NATO's principle response force has officially passed to the UK this morning.
The Allied Rapid Reaction Corps or ARRC based in Gloucestershire is now in command of the enhanced NATO Response Force which must be ready to deploy to any global threat within hours.
The force will comprise of 3,000 British troops standing ready, supported by NATO allies, to respond to any threat to the alliance.
The US, Denmark, Spain, Norway and Poland will support the UK brigade, adding capabilities such as armoured infantry companies, aviation and mechanised infantry.
The Royal Air Force has also taken the lead in the air component of the NATO Response Force.
Defence Secretary Sir Michael Fallon said:
"With the Alliance’s second biggest and rising Defence budget, Britain is at the heart of NATO. In heading up the VJTF, the UK is taking another leading position in NATO and is sending a clear message that Britain is stepping up to our global defence commitments.
The UK’s Armed Forces stand ready, at a moment’s notice, to defend our allies and protect the British national interest.
Leading the NATO Very High Readiness Joint Task Force is the first of a stream of activity which will see the UK stepping up its leading role in NATO."
The UK will also deliver one of four battalions to NATO’s enhanced Forward Presence in the Baltic States and Poland, with a battalion being sent to Estonia from early 2017 and a company deployed to Poland.
In October, the Defence Secretary announced that the UK would commit RAF Typhoon aircraft to the NATO Southern Air Policing mission, offering reassurance to the Black Sea allies.
Deployed from RAF Coningsby, the Typhoons will be based at Mihail Kogălniceanu Airbase, Romania for three months in summer 2017.