Likewar, written in 2018 by Emerson T. Brooking and P. W. Singer, provides an overview of how propaganda and advertising has become exponentially more powerful via social media. Brooking and Singer argue that social media has been effectively weaponised by several groups including the Islamic State, and they also highlight how Russia and Donald Trump have successfully mastered social media as a tool to advance a political agenda.

Brooking and Singer take a historical lens to social media, drawing analogies between recent events and older tactics. For example, they highlight the way the Islamic State used social media to publicise the capture of Mosul in Iraq. The battery of social messaging around this advance was likened to the broadcasting of the German blitzkrieg to demoralise the French in World War II. Similarly, they compare Russians who use online American personas to agents of the Soviet Union employing similar tactics in the Cold War.  

The authors use history and research to inform the public of the strength of the threat posed by weaponised social media. They highlight how several groups have already mastered the “4D’s” – “Dismiss the critic, Distort the facts, Distract from the main issue, and Dismay the audience.” Moreover they emphasise that the threat will only continue to grow. Political actors can use social media to sway public opinion and drive behaviour. Brooking and Singer show that readers are more easily convinced by a message that has been repeated many times, even if there is some doubt about its veracity.

In short, the authors create a case to argue that cyber security should be about more than blocking hackers and that the spread of infectious and false messages levied by nefarious parties could be much more detrimental to global democracy.