More than half the Arctic's coastline is Russian territory and in the last six years Moscow has built more than 475 military ...

US President-elect Donald Trump has called on Nato's European members to spend 5% of their national incomes on defence. That is more than double the military alliance's current target of 2%.

The vast majority of the world's data runs through undersea cables, which can be exposed to attacks under what is known as hybrid warfare.