My research spans the fields of history, 'transitional justice' (the search for accountability after political transitions and regime changes), and 'memory studies' (processes of remembering, forgetting and representing the past). Empirically, my research explores the handling of the Nazi and communist legacies in Germany and beyond. Building on my previous work, including my first book on unified Germany's handling of the East German communist past, my research has had three related areas of emphasis.

First, I have become a recognised authority on the politics of memory in contemporary Germany, especially the connections and competitions between the Nazi and the communist pasts.

Second, I have contributed to the interdisciplinary field of transitional justice, looking beyond Germany to consider post-communist Eastern Europe more broadly.

Third, I have pursued an ambitious project on a neglected and misunderstood aspect of post-Nazi transitional justice: the victorious Allies' internment of over 400,000 German civilians in postwar Germany.

My 2020 book, Allied Internment Camps in Occupied Germany, published by Cambridge University Press, has received overwhelmingly positive reviews in the leading journals in the field:

- 'impressive', 'systematic', 'nuanced', 'persuasive', 'Beattie's book will interest all historians of the postwar occupation of Germany' (Central European History)

- 'powerfully argued', 'the depth and insight of this book, written by an expert in post-war German history, make it highly valuable reading for those interested in the Allied occupations, transitional justice and the legacies and aftermath of Nazism' (German History)

- 'clear and decisive', 'this book's contribution to understanding the similarities and differences between the occupying powers is unrivalled', 'the depth and range of the sources is striking' (European History Quarterly)

- 'an essential contribution' (H-War).