Phillip Deery is an historian of the Cold War with a special interest in the impact of communism, anti-communism and espionage on the politics and culture of Australia, Great Britain and the United States.

He has authored more than 100 scholarly publications in the fields of Cold War studies, intelligence and national security, labour movement history and Communist Party history.

In this, his most recent book, he describes the ‘sparrows’ of the title as ‘an indispensable means of acquiring information about communists and left-wing organisations and activists’. Sparrows went undercover in suspect organisations. Their activities were shrouded in secrecy, their anonymity protected, with the exception of several cases Deery writes about.

But let’s backtrack. In the wake of the Second World War and the realisation that the Soviet Union had set up extensive espionage networks around the world, Australia responded by establishing its own spy-hunting agency: ASIO.

By the 1950s its counterespionage activities were increasingly supplemented by attempts at counter-subversion – identifying individuals and organisations suspected of activities that threatened national security.

In doing so, it crossed the boundary from being a professional agency that collected, evaluated and transmitted intelligence, to a sometimes politicised but always shadowy presence, monitoring not just communists but also peace activists, scientists, academics, journalists and writers.