Royal Marines are experts at fighting a winter war

War on terrorism: Front line

The United States, Britain and their allies will almost certainly be fighting a winter war in Afghanistan, and the Royal Marines of 3 Commando Brigade, Britain's frontline winter warriors, are expected to play a crucial part.

The brigade, made up of the units 40 and 45 Commando plus reinforcements, is based at Plymouth. Its members are experienced in Arctic and mountain warfare and their main training takes place in northern Norway by a team of 25 instructors.

The marines operate in four- man units and learn how to survive in snowholes they have built. Their bergens, or military rucksacks, weigh up to 80lb and contain the necessary equipment to fight both in the slopes and below the treeline.

The commandos standard weapons are the SA80A2 rifle, light support weapons, general purpose machine guns, 94mm anti-tank weapons, and grenades. They are protected by kevlar helmets with white coverings and plastic, and insulated snow shoes can be attached to their boots. Their skis are glass fibre with special quick-release bindings.

Each marine will also carry a sleeping bag, a bivvy bag to keep dry, a snow shovel and food for two days. The four-man team, between them, will have a four-man tent, naptha fuel, and "helicopter panels" – day glow panels for pinpointing landing sites.