Kathrine Frich
He now fights against his old brigade.
Armies spend millions on radar and satellites to spot enemy movements from miles away.
None of that technology helps when the biggest threat is standing right inside your own camp.
For one brigade in eastern Ukraine, the deadliest weapon on the battlefield was a young officer holding a smartphone.
Seconds to run
Russian Lieutenant Lev Stupnikov looked like a loyal soldier after graduating from a top military academy in St. Petersburg. Instead, the 26-year-old became a ruthless mole who helped Ukrainian forces kill more than 300 troops from his own brigade, according to the Wall Street Journal and Digi24.
His mother, Tatiana, had connected him with Dmitro Karpenko, a programmer working with Ukrainian military intelligence.
On a freezing February morning near Vuhledar, Stupnikov secretly photographed a training ground and sent the coordinates to his handler. “There must be between 120 and 150 people here,” he texted.
His Ukrainian contact urgently told him to get away, typing in capital letters: “LEAVE.”
Faking a stomachache, the lieutenant grabbed some tissues and walked toward the trees just before Ukrainian missiles struck, killing 68 Russian soldiers and wounding 60, including commander Colonel Gusein Musayev. When his handler asked for a photo of the blasts, Stupnikov texted back: “It’s just meat.”
Escape and betrayal
Horrified by images of bombed Ukrainian cities, Stupnikov called the invasion “diabolical” after being sent to the front “to replace the losses” in a unit filled with untrained conscripts and former prisoners.
Over the following months, he leaked radio frequencies, disabled security cameras, and broke Russian drones so they overheated.
As his unit’s losses mounted, a baffled commander complained: “Nothing we do works. I have the feeling that there is a Stierlitz among us,” referencing a famous fictional Soviet spy.
By July, with suspicion growing, Karpenko arranged a password for Stupnikov to walk unarmed across the lines.
He now fights against his old brigade alongside anti-Kremlin Russians in the Russian Volunteer Corps. While his mother and sister joined him in February 2025, his wife, Liza, stayed in Russia and later told Russian state media: “He betrayed me too.”
Still, Stupnikov told the Wall Street Journal he stands by his choice: “Did I break my oath? I promised to defend freedom, independence and constitutional order. But Putin destroyed all three.”
