If you have been in Cumbria and southern Scotland recently, you can't fail to have noticed a lot of military activity.
Thousands of troops from around the world are taking part in a huge military exercise called Operation Joint Warrior.
Hannah McNulty went to see them in action:
More than 3,000 troops are taking part in "Operation Joint Warrior" in and around Galloway Forest in Dumfriesshire.
A group of British and French paratroopers are also carrying out a parachute drop near to the Braid Fell area.
More than 3,000 troops including British and French paratroopers are taking part in a joint training exercise in the Galloway Forest near Dalbeattie.
It will involve a parachute drop in the Braid Fell area, as well as a substantial amount of fixed wing and helicopter flying.
Routine movement of MOD vehicles can be expected between Galloway Forest and the north of Dalbeattie, and convoys may be present on the A75.