This one is a real treat for military history buffs. Britain emerged from the Second World War in financial crisis, but the development of the jet engine provided hope for the future and resulted in a world-leading aviation industry. In the first of a two-part documentary, historian and author James Holland examines how the jet became a lucrative export and a powerful piece of military hardware during the Cold War, and looks at how selling to the wrong buyer could alter the balance of power. It's fascinating stuff.