Some of the bravest people fighting against Vladimir Putin’s war on Ukraine are Russians themselves. But you won’t have heard of them. You probably never will. 

These are not the soldiers carrying Ukrainian flags nor dissidents protesting in Moscow. They are the secret agents operating inside Russia’s military, risking everything to undermine a war they never believed in and have come to despise. 

Their extraordinary stories deserve far more attention. 

A BBC documentary, , out this week, shines a light on the clandestine world of Russian and Ukrainian agents working against Moscow’s invasion. It arrives alongside remarkable reporting by about a young Russian officer whose betrayal of Putin helped Ukraine conduct devastating strikes against Russian forces. 

These are the unsung heroes of the shadow war. They show the enduring impact of human intelligence (Humint) — real spies risking their lives — against the backdrop of a technological revolution in warfare.

Nothing can yet replace the value of a human being with knowledge and the courage to use it when it matters most. 

The ‘s investigation details the extraordinary exploits of 26-year-old Russian Lieutenant Lev Stupnikov, who secretly supplied Ukrainian intelligence agencies with troop locations, operational plans and other vital information while serving in military. According to the reporting, his intelligence contributed to Ukrainian attacks that killed more than 300 Russian soldiers, including senior officers. 

Stupnikov ultimately escaped across the front lines to Ukraine in 2024. His transformation from Russian officer to clandestine Ukrainian intelligence asset illustrates something often overlooked in discussions of the war: the Kremlin’s soldiers can become some of its most dangerous adversaries. 

As a former CIA station chief who spent much of my career confronting Russian intelligence operations, I find these stories particularly compelling, and they remind me of my own experiences working with what I call “hero spies”. 

Like many of my CIA colleagues who worked against Russian intelligence, I developed enormous respect for the Russian people, even as I detest the methods of their intelligence services — the FSB, SVR and GRU. We must never confuse the Russian population with the repressive security apparatus that serves Putin’s Kremlin. 

Some courageous Russian citizens are prepared to resist that apparatus from within. Putin’s intelligence services represent the worst of the often-ruthless world of security services and Russian repression – its corruption, coercion, deception and institutional culture of entitlement. Yet that story has another side. The same system that demands unquestioning loyalty can produce deeply disillusioned insiders, willing to risk their lives to expose and undermine it. 

Intelligence professionals have long understood this paradox. 

During the Cold War, Soviet military intelligence officer Oleg Penkovsky supplied the West with invaluable intelligence about Soviet military capabilities, helping inform American and British assessments during the Cuban Missile Crisis. His extraordinary contribution came at the ultimate price: the Soviets discovered his espionage and executed him.  

Penkovsky kept spying even when he and his handlers believed he may have been compromised. He wanted to do the maximum damage to the system he came to detest. Adolf Tolkachev, the “billion dollar spy”, was another such agent working for the CIA, penetrating the Russian scientific establishment. These hero spies gave their lives to help the West. Many more are risking the same today. 

Some are motivated by conscience, others by disillusionment, revenge or money. Not every spy, however, is a hero, and no professional intelligence officer should assume that noble motives accompany every act of betrayal. 

However, individuals who act from genuine moral conviction occupy a special place in intelligence history. And their contribution remains indispensable. 

We live in an era of satellites, AI, cyber operations, drones and precision-guided weapons. Yet even the most sophisticated technology cannot reliably reveal what a commander intends to do tomorrow, what orders have been issued behind closed doors or which vulnerabilities exist inside a military formation. 

A well-placed human source, sometimes, can. Satellites can show where the tanks are. A spy can tell you where they are going — and why. 

These spies remind us how traditional Humint can transform battlefield outcomes when combined with modern weapons and surveillance. But what makes these individuals remarkable is not merely their operational effectiveness, it is the extraordinary personal risk they accept. 

Espionage is not James Bond. It is fear, isolation, deception and the constant possibility of discovery. Agents live double lives, sometimes deceiving their closest colleagues and loved ones. Exposure can mean imprisonment, torture or death — and potentially grave consequences for their families. Russian counter-intelligence and internal security services have extensive powers and are formidable adversaries. 

The danger doesn’t necessarily end when an agent escapes. The individual and family members may remain vulnerable. 

The spy’s greatest enemy isn’t always a gun. It’s the fear of discovery — and knowing your family may pay the price. Even a successful escape may not end the danger. 

A profound moral dilemma also looms for many of these agents. They are providing battlefield intelligence that will lead or has led to the deaths of men who wore their own uniform. These Russians — like generations of spies before them operating behind the lines of corrupt and autocratic regimes — conclude that serving an invading army represents a greater betrayal of their principles than helping to stop it. 

That distinction matters, and makes them true heroes. It also brings espionage the attention it deserves for its importance during war. Wars are not fought exclusively by armies, missiles or drones. They are shaped by individual decisions made in secrecy, often without recognition or reward.

The names of many agents will never become public. Their sacrifices may remain buried in classified files for decades. At the CIA, we remember that our failures are always public, but our successes usually are not.

After a career confronting Russian intelligence, I am convinced that one of the greatest threats to an authoritarian system is the individual within it who finds the courage to say no. We need them in the West. We are waiting for them – we will greet them with open arms, just as Ukraine is. We will validate and vet them, and many will go on to accomplish great wartime feats of bravery. 

History teaches us that the contributions of spies can be consequential far beyond their numbers – Penkovsky, Tolkachev, GRU General Dmitri Polyakov, SVR Colonel Sergei Tretyakov and others – the heroes then and now.

Sometimes the greatest act of loyalty to one’s country is refusing to betray one’s conscience. And sometimes the greatest heroes of a war are those fighting it from the shadows.

Sean Wiswesser is a former CIA station chief and expert on Russian intelligence, espionage, and defence issues. He is the author of ‘Tradecraft, Tactics and Dirty Tricks: Russian Intelligence and Putin’s Secret War’ (Naval Institute Press, 2026)

All statements of fact, opinion, or analysis expressed are those of the author and do not reflect the official positions or views of the US government. Nothing in the contents should be construed as asserting or implying US government authentication of information or endorsement of the author’s views