We live in an age of subterfuge. Spy agencies pour vast resources into hacking, leaking and forging data, often with the goal of weakening the very foundation of liberal democracy. Thomas Rid, a renowned expert on technology and national security, was one of the first to sound the alarm. Even before the 2016 US election, he warned that Russian military intelligence was ‘carefully planning and timing a high-stakes political campaign’ to disrupt the democratic process. But as crafty as such so-called active measures have become, they are not new. In ‘Active Measures’, Thomas takes the reader on an astonishing journey through a century of psychological war.