We have been perfecting our influence for millions of years, but in the last 20 years digital technologies have revolutionised how influence works. We are now connected to old school friends and niche interest groups – but unwittingly also to organised criminals, terrorists and hostile states who infiltrate our societies. The course of history is being shaped: elections have been hijacked, lies spread about pandemics and the rapidly heating climate, and information has become as important as bullets and bombs to winning wars. More than ever, influence has become the crucial currency for commercial and political gain: If you don’t understand it, you will likely become its victim.