The news could hardly be worse. Across Britain, tens of thousands of terrified people are streaming out of the major cities. Looting is widespread, while every day brings bomb attacks at railway stations and RAF bases.
Abroad, the Red Army has sliced through the West’s defences, using chemical weapons to punch through Nato’s front lines. Yugoslavia has fallen, and West Germany and Norway are on the verge of succumbing.
After four days of Russian air raids, killing hundreds of people in Glasgow, Liverpool, Manchester and Southampton, Mrs Thatcher faces the ultimate decision. On her desk is a message from the Supreme Allied Commander in Europe, asking for authorisation to launch a nuclear attack across the Iron Curtain.