The British Army's Desert Rats have been preparing to join Nato's Very High Readiness Joint Task Force, training on the Sennelager Ranges in Germany.
From January 2024, the 7th Light Mechanised Brigade Combat Team will lead the 5,000-strong, multinational rapid response force.
The Very High Readiness Joint Task Force (VJTF) forms part of a larger Nato response force of 40,000.
Brigadier Guy Foden, Commander, the Desert Rats, told Forces News the force is "as the name suggests, very high readiness".
"I won't go into the exact profile, but it is within days this brigade could be moving to wherever Nato needs it to go," he said.
"It's nine nations in the brigade so there's a lot of focus on interoperability."
Joining the 7th Light Mechanised Brigade Combat Team for training in Germany was an Albanian contingent, 2nd Battalion, the Royal Anglian Regiment and the Royal Scots Dragoon Guards.
The training saw personnel encounter a full range of 'threats', with Brig Foden saying the training is set in a "fictional country" with fictional threats covering everything from "criminality up to a major armed invasion".
The VJTF was created after Russia's annexation of Crimea in 2014 and was first mobilised in February 2022 after Moscow's full-scale invasion of Ukraine.
"It's important that we're ready and the security situation in Europe is what it is," Brig Foden said.
"It is certainly a challenging environment at the moment which just gives an added impetus to the requirement to be ready for what could come."