The British Army in 2017 is in unchartered territory. They haven't been at war for three years. After controversial campaigns in Iraq and Afghanistan there is political and public opposition to military intervention overseas. The Army's budgets are under pressure and they have the smallest troop numbers since the days of Cromwell. But with the rise of the so-called Islamic State, the threat of a new cold war in Eastern Europe and famine and conflict in Africa, the British Army has to play a new role in a deeply unstable world.