Prior to last year, Philippe Sands was perhaps best known as the barrister who laid out a methodical take-down of the British government’s legal case for war in Iraq.  In 2005’s Lawless World, Sands displayed a extensive knowledge of international law and legal history, something he would call upon again for the 2016 Baillie Gifford prize-winner East West Street. It is this latest book, a legal history-cum-memoir, which has brought him true international renown, and which drew a sold-out audience to hear him speak at this year’s Edinburgh International Book Festival.

During his talk, Sands expressed genuine surprise at the overwhelming response the book has received, telling as it does a rather personal family history intertwined with the 20th century development of “genocide” and “crimes against humanity” as legal terms. He was also completely unaware of the enhanced relevance the book’s subject matter would have post-Brexit, with the new potential for a breakdown of post-1945 legal frameworks designed to safeguard against such heinous crimes. The most interesting part of the event, though, was Sands’ reading of a brand new chapter for East West Street which has been commissioned jointly by the book festival and Baillie Gifford, a piece which also served as a summary of the book’s main themes.

In his new chapter, Sands warned against the spread of xenophobic nationalism that is currently sweeping the USA and much of Europe, a divisive ideology that threatens the international bridge-building which arose in response to the Third Reich’s atrocities. He also chronicled the many communications he’s received since East West Street was published from people with personal connections to Lviv, the Ukranian city at the centre of his narrative. What emerges from this intersection of the personal and political on the grandest possible scale is, as Sands himself was keen to reinforce, the desperate need for human beings to rediscover the idea of a global citizenry. By focusing on our differences rather than our similarities, he suggested, we run the risk of undoing many of the great political achievements of the last seventy years. We must be wary of the fragility of the relative peace that has prevailed since the end of the second world war, and mindful of the parallels between Europe and America in this decade, and the Poland and Germany of the 1930s.

In a world where both Britain and the USA cling desperately to the last glimmers of an imperial power in decline, unlearning the essential lessons of history which founded the institutions constraining belligerent states, Sands’ book is becoming more and more relevant with each passing day.