NATO's biggest exercise in more than a decade, Exercise Trident Juncture, has got underway in Norway with 31 nations taking part.
The exercise is designed to test capability and interoperability between the nations, in response to a potential attack.
Two hours from the capital city of Oslo, 1,600 British soldiers have setup base at Haslemoen camp - the starting point for the exercise.
More than 250 armoured vehicles and 500 soldiers from the British Army made the journey after stopping in the Netherlands.
What happens to the military's kit when it arrives by air and sea?
It took seven days for British personnel and equipment to reach Haslemoen along with their Danish and Polish allies.
The British Contingent Commander Officer says the UK's involvement is proof of their capability, resolve and honour of treaty commitments.
"It's just vital, that certainly within Europe and NATO's borders, we can deploy significant force over a significant distance of two-and-a-half thousand kilometres and be ready to fight at the end of it," Colonel Nick Theakston explained.
"We've prosecuted a multi-modal deployment by rail, air, road and ferry.
"We're here in one piece and ready to go."
With 50,000 troops taking part, logisticians from each nation have played an important role.
Haslemoen's field storage area holds all the rations, fuel and clothing needed for British troops not just to battle the enemy but also Norway's harsh climate.
Royal Logistic Corps (RLC) were set the task of driving supplies two hours north to ground troops, with the risk of black ice making vehicle suitability a large focus.
Lieutenant Kathryn Smith, 62 Squadron 6RLC, said: "We don't necessarily know how much they'll request each time.
"So each day is different and different demands of rations, ammunition, fuel - it just depends on what's happening on the day."
Soldiers from Royal Irish and Duke of Lancaster’s Regiments are some of the personnel that will be assisted by the RLC.
As land infantry, they would likely be deployed as a follow-up force behind the Royal Marines on an operation.
Lieutenant Matt Tilley, 1 Royal Irish Regiment, said: "The conditions aren't as severe as, let's say, up in the Arctic Circle.
"But, if we had to deploy this capability, we have the opportunity to train and make sure we understand how that works.
"It's just having more strings to your bow, than entering this type of theatre blind."
Food For Thought
During Exercise Trident Juncture, 175,000 meals will be produced by 42 chefs (27 from the British Army Regular, eight from the Reserve and seven from the Danish Army).
How the chefs in Norway stop personnel on Exercise Trident Juncture from going hungry.
The 175,000 meals include:
- 250,000 (87,500 litres) of tea and coffee - the equivalent of four Close Support Tankers or 12.5 Unit Support Tankers
- 17 tonnes of potatoes - the same weight as an unladen Enhanced Pallet Load System or three Jackals
- 50,000 breakfast sausages - which would be around three miles long if laid end-to-end
- And 66,000 eggs - the weight of a basic Land Rover, or if laid end-to-end, more than three miles long