The Secret History of the Five Eyes
The Untold Story of the International Spy Network
Richard Kerbaj, Union Square, 2025, 448 pages
Book Review published on: July 21, 2025
Today, in the information age, intelligence operations frequently propel the formation of grand strategy and accompanying policy. So, intelligence is a critical and valuable commodity. But be that as it may, the clandestine world of espionage, from which this intelligence is harvested, remains enigmatic. "Until 2010, the existence of the Five Eyes was a closely kept secret. Even now, it remains the world's most powerful, but least known, intelligence network."
Richard Kerbaj's The Secret History of the Five Eyes: The Untold Story of the International Spy Network offers up a fascinating exploration of one of the most important, and until recently, covert intelligence alliances ever created. So, what exactly is "Five Eyes"? Well, it's an alliance of sorts, initially forged between the United States and the United Kingdom during the dark days of World War II. In 1946, this ad-hoc alliance was formalized in the UK-USA Agreement, a treaty covering joint cooperation in signals intelligence. As the Cold War deepened, the agreement was further formalized under the Echelon surveillance system of the 1960s. From its humble beginnings, it eventually came to include Canada, Australia, and New Zealand, all English speaking former colonies of the British Empire. The term "Five Eyes" originated as shorthand for a "AUS/CAN/NZ/UK/US EYES ONLY" releasability caveat.
Kerbaj begins by laying out the origins, evolution, and peculiarities of this unprecedented intelligence alliance, an alliance many countries would kill to get into but have not been offered an invitation to date. Why these five countries and no others? Established under the ominous clouds of war, the alliance has matured from a wartime necessity into a rather sophisticated intelligence-sharing system that impacts global security. Usually, spy networks run by individual countries are loath to divulge secrets to other foreign agencies, if for no other reason than it has the potential to compromise their sources, methods, and means. So, the notion of two, let alone five, nations getting together to collectively address pressing security issues they face is an interesting idea, to say the least. That the alliance has endured despite numerous episodes of turbulence between and amongst the members speaks volumes about the importance each participant places in the liaison.
The story of Five Eyes begins in the cauldron of war against an existential threat, in the east and the west. The development of signals intelligence and the creation of secure communications helped foster the growth of the pact. We get an insider's view of early intelligence breakthroughs, including the breaking of Enigma and Japanese communications, both of which contributed mightily to the Allied war effort. Forged in one war, the alliance had to adapt to the changed circumstances of a markedly different war—a Cold War, complete with the overarching and ever-present threat of nuclear annihilation. During this long, tension-filled period, the monitoring of Soviet missile developments swallowed considerable bandwidth, as did spy activities aimed at understanding Soviet military capabilities. While the United States provided the preponderance of assets and intelligence, thanks to its huge budget, other partners proved useful to U.S. interests in myriad ways. Of course, they reaped many rewards from their collaboration with America too and were averse to doing anything that might jeopardize the continued flow of "grade A" intelligence. That said, it was not always easy managing and coordinating intelligence operations across multiple nations with differing political agendas and priorities. It was useful to see how the actors were able to overlook transgressions and screwups, not always an easy thing to do, and keep uppermost in their considerations the larger picture. Despite headaches, some irritating personalities, and sometimes misaligned processes, the architects of this alliance must be congratulated for maintaining a cohesive and effective intelligence-gathering machine. In the post-Cold War era, the alliance had to transition once more to face new global security challenges such as terrorism. The shift in focus from conventional state actors to asymmetric threats was not a simple or frictionless transition, but they managed to pull it off, collaborating on a host of operations in the wake of the 11 September attacks. The Five Eyes worked tirelessly across the globe and across borders to track and disrupt terrorist networks while simultaneously sharing intelligence and insights on a global scale in support of counterterror operations. Concurrent with these developments were various technological advances to include cyber capabilities. And while these developments have enhanced their collective capabilities, these same technical leaps have made their task harder.
One of the more compelling portions of the book is where Kerbaj offers up detailed descriptions of particular intelligence operations carried out by members of the alliance. These case studies afford the reader valuable transparency into the high-stakes environment of espionage, keeping tabs on high-value targets, intercepting critical communications, and carrying out covert activities, thereby shedding light on the vital role intelligence plays in shaping outcomes. The reader comes away from these valuable snippets with a pronounced appreciation for the intricacies of intel operations. To be successful in this high-stress, high-octane world full of bad actors with bad intentions requires precise intelligence, timely decision-making, and efficient and effectual coordination to achieve strategic objectives.
Of course, any discussion of Five Eyes that fails to breach some of the more notable controversies surrounding the alliance would be remiss. Former National Security Agency contractor Edward Snowden once described Five Eyes as a "supra-national intelligence organization that does not answer to the known laws of its own countries." To Kerbaj's credit, he does not shy away from addressing ethical and operational conundrums faced by members to include privacy, surveillance, and international relations. Often, these discussions revolve around the balance between security and civil liberties. Several recent abuses, or instances of obvious overreach, not to mention sovereignty issues and the demands and responsibilities of collective security, are touched upon. It must be said the author delivers a fairly balanced assessment, demonstrating a nuanced view of the ethical considerations tangled up in intelligence and surveillance ops and the importance of upholding transparency and accountability within democratic systems like those of the Five Eyes.
The book is highly recommended for those fascinated by the confluence of intelligence, strategy, and security. Kerbaj does an excellent job of illuminating the inner workings of Five Eyes and highlighting the inestimable role intelligence plays in shaping and contouring the global arena in which all actors vie for advantage. His writing reminds one of how complex and shadowy the world of espionage is and the value of good intelligence in sustaining global order.
Book Review written by: Lt. Col. John H. Modinger, PhD, U.S. Air Force, Retired, Fort Leavenworth, Kansas
Notes
1. Richard Kerbaj, The Secret History of the Five Eyes: The Untold Story of the International Spy Network (Union Square, 2022).
2. Intelligence and Security Committee of Parliament, Detainee Mistreatment and Rendition: 2001-2010, 2018, HC 1113, https://isc.independent.gov.uk/wp-content/uploads/2021/01/20180628-HC1113-Report-Detainee-Mistreatment-and-Rendition-2001-10.pdf.
3. Katie McQue, "Watchdog Accuse Apple of 'Clearly Underreporting' Child Sexual Abuse Materials (CSAM)," MacDaily News, 22 July 2024, https://macdailynews.com/2024/07/22/watchdog-accuse-apple-of-clearly-underreporting-child-sexual-abuse-materials-csam/.