Many of the characters in the novel are historical figures, including Karl P. Cohen, Harold Urey, Leslie Groves, Richard Feynman, Freeman Dyson, Moe Berg, Werner Heisenberg, Wilhelm Canaris and Erwin Rommel.

[4] Teller had worked in the Manhattan Project during World War II, and told Benford that a decision made in 1942 turned out to be a costly mistake that delayed the development of the atomic bomb by a year.

[3] Cohen believed that had they been allowed to continue working with centrifuges, the problems they were having would have been overcome, and the bomb would have been ready to deploy in 1944, bringing the war to an early end and saving millions of lives.

In August 1944, Cohen and US Strategic Services agent Moe Berg travel to Switzerland for a secret meeting with German physicist Werner Heisenberg to establish the progress of Germany's atomic bomb project.

Heisenberg admits that Germany has no bomb program, but tells them that the idea of deploying radioactive dust came from von Braun, who had read about it in a science fiction short story.

In a review in Locus magazine, American science fiction writer Paul Di Filippo described The Berlin Project as alternate history in the style of Harry Turtledove that has a "plain yet gripping effectiveness", not unlike Michener or Wouk.

[6] Di Filippo approved of Benford's choice of Karl P. Cohen as the book's protagonist, saying that using a "lesser-known ... slightly off-center" scientist from the Manhattan Project adds an interesting perspective to the story.

"[6] British literature scholar Tom Shippey wrote in The Wall Street Journal that The Berlin Project is all about "[p]hysics and politics, engineering and imagination".

[9] Reviewing the novel at the New York Journal of Books, Lenaburg said the "wonderful blend" of historical figures and fictional characters are "all handled in a completely realistic and believable manner".

[10] Spinrad called the novel "a fascinating true history", adding that Benford "manages to ... make the science and technology and its personal and political conflicts and tensions dramatically exciting".