A world leading expert on intelligence, national security, and geopolitics — a scholar at Harvard University’s Kennedy School of Government. Read More >

I’ve written
two books.

My new book, published in June 2023, is SPIES: The Epic Intelligence War Between East & West (Simon & Schuster/Little Brown). Described as “explosive” by CNN and “riveting” by the Economist, it takes readers inside the shadow conflict that has raged between Russia and the West for over a century. My first (award -winning) book, EMPIRE OF SECRETS (Harper-Press 2013) was a gripping account of British intelligence during the last days of the empire century. Read More >

I write about public policy.

Helping to run the Applied History Project at Harvard’s Kennedy School, I engage widely with the public and policy-makers. Through commentary, and by contributing to broadcast programs, my work brings historical perspectives to present-day intelligence and national security affairs. Read More >

I Comment on Current Events.

“A masterclass in 20th century and contemporary history” —Fiona Will

Now Published

SPIES takes readers inside the intelligence war that has raged between Russia and West for over a century.

 Buy Now > 

“A masterpiece!...” —Christopher Andrew “A masterpiece!...” —Christopher Andrew “A gripping, authoritative work.” —Kirkus Reviews “A gripping, authoritative work.” —Kirkus Reviews “The book we have all been waiting for.” —Brendan Simms “The book we have all been waiting for.” —Brendan Simms

Spies Reveals a Russian Assasination plot in the US

After its publication in June 2023, SPIES received front page news in the New York Times: that in 2020, Russian intelligence was in late-stage planning of an assassination on U.S. soil. More broadly, the book takes readers inside the intelligence war that has raged between Russia and the West for over a century. Centering on key characters, never-before seen archival research in multiple languages and countries, and a synthesis of dramatic storytelling, it explains Russia’s war underway in Europe in 2022 and provides a chilling warning about the superpower clash underway this century: between the United States and China. Whether we like it or not, the West is already in a New Cold War.

The book is by Calder Walton, a scholar of national security and intelligence at Harvard, The New York Times independently confirmed his work and is reporting for the first time on the bitter fallout from the operation, including the retaliatory measures that ensued once it came to light.

Praise for the Book

“Calder Walton’s deeply researched and artfully crafted book offers a masterclass in 20th century and contemporary history. It is rich with trenchant analysis, surprising details, cautionary tales, and unique insight into the ‘hundred years war’ between American and Russian intelligence agencies. Spanning the Bolshevik Revolution to the war in Ukraine, it is essential reading for anyone trying to understand the complicated trajectory of current events.”

—Fiona Hill, deputy assistant to the U.S. president and senior director for European and Russia on the U.S. National Security Council from 2017 to 2019

“A major work, and a vivid and important history. Calder Walton shows his ability to change our understanding of the end of Empire by reinserting the missing intelligence dimension—comparable perhaps to the way Bletchley Park and ULTRA have changed the history of WWII.”

—Christopher Andrew, author of Defend the Realm: The Authorized History of MI5

"SPIES contains valuable lessons for the present. As with the Soviet Union and Putin’s Russia, the US and its allies have been slow to recognise China’s threat. Its economic weight makes the country more challenging and potentially dangerous than the Soviet Union. Beijing, like Moscow, has also engaged in massive technological transfer from the west, or “spying and buying” as Walton calls it."

—Financial Times

"Calder Walton’s 'SPIES' is a riveting history of espionage...'SPIES' explains how espionage and covert action shaped the cold war, but its enduring message is the folly of failing to realise you are in an intelligence war in the first place."

—The Economist

"SPIES grabs you from the opening page and never lets go. One of our foremost historians of the East-West intelligence war takes us deep inside this grand and often spine-chilling struggle, which predated the Cold War and still rages today."

—Fredrik Logevall, Pulitzer Prize-winning author of Embers of War