It is now widely believed that Russia and its agents interfered with the 2016 US presidential election to help Donald Trump get elected. In Collusion: How Russia helped Trump win the White House, journalist and author Luke Harding investigates the likelihood that Trump and his associates colluded with Russia to achieve that goal.

It is not an easy task. At first blush, the idea itself seems fantastical – the stuff of Cold War novels or conspiracy theories. Further, Harding is delving into the non-binary world of intelligence, where there are no definite truths, only ‘degrees of veracity’. Identifying and evaluating information from within the murky and incestuous world of post-Soviet Russia – a world where ministers, spies, and oligarchs do Vladimir Putin’s bidding as the sine qua non of survival – presents challenges, as does piercing the veil of Trump’s sprawling, often opaque, business empire.