[1] In a 2022 interview with The Review of Democracy's editor Ferenc Laczó, Specter discussed his interest in Carl Schmitt, Hans Morgenthau, and Wilhelm Grewe, highlighting their relevance to understanding political thought.

He examines key figures such as Carl Schmitt, Hans Morgenthau, and Wilhelm Grewe, revealing the complex interplay of geopolitical analysis and national interest shaping realist perspectives.

[3] In her review of the book published by Foreign Affairs, and comparing it with Jonathan Kirshner's An Unwritten Future, Emma Ashford described Specter's study of realism as "an impressive contribution" but found the lessons that he draws as "less convincing".

The reviewer noted that many thinkers and philosophers "reach to past for inspiration and support" and that one shouldn't blame classical realists for seeking a "longer, more diverse lineage for their ideas".

Mearsheimer traces back the roots of his theory to classic thinkers such as Thucydides and Machiavelli, whereas Specter draws a line back from the late 19th century's naval historians and geographers such as Friedrich Ratzel and Alfred Mahan, to influential German politicians and legal theorists such as Karl Haushofer and Carl Schmitt, and then to classic texts of American realism, revealing the "dark roots in the imperialist era" of realism.

However, Kelly suggested that recent scholarship has uncovered the exclusionary nature of realist thought, prompting a reevaluation of its imperial origins and implications for contemporary political teaching.

In her review of the book, Michaela Hoenicke Moore wrote:This is an important contribution by a scholar of modern German intellectual history to the growing literature (Udi Greenberg, Nicolas Guilhot, Daniel Bessner, and, from a different angle, Stephen Wertheim) on the elective affinities and entangled German and American roots of Realism, here defined as that International Relations (IR) school which offers guidance on geo-politics and world power.