Ukrainian civil society is teeming with activists carrying weapons, equipment, food and medicine to soldiers on the front line. A reserve officer and radio transmission expert, Serhiy Beskrestnik, 49, has found a unique and solitary mission: preaching electronic hygiene.

Via his Telegram channel which counts 81,000 subscribers, "Flash" (his nom de guerre) tirelessly dispenses advice: How to escape Russian drone surveillance and the strikes that follow; how to protect sensitive communications and how to decipher the code; how to protect sensitive communications and decrypt those of the enemy; to jam enemy drones without jamming your own. He is raising awareness of the rapid evolution of electronic warfare. His target audience is broad: from the high command to the soldier in the trenches, from civilians close to the front to industrialists working behind the scenes.

The clock is ticking. The Russian army is making rapid progress, both in industrial production and in the tactical integration of electronic warfare systems. The Zala, Supercam and Orlan reconnaissance drones are constantly circling the skies, casting their cameras over a 70-kilometer-deep strip behind the Ukrainian front, day and night. "They watch all military vehicles. Once spotted, they are tracked to their unit or parking position, where they are struck," said the jovial, bearded engineer in military garb, who worked for the French group Sagem (now Safran) in the early 2000s.

The time between detection and strike is sometimes very short, less than 10 minutes. Hence Beskrestnik's advice: "Near the front, military equipment must be systematically camouflaged under greenery or buildings. Avoid busy service stations, which are systematically monitored. Avoid parking for more than 10 minutes in an open area, and always keep a distance of more than 50 meters between vehicles."

The Russian Lancet kamikaze drone, which works in tandem with the Zala reconnaissance drone, can strike moving targets, like that BM-21 rocket-launching truck destroyed while driving on a road north of Kharkiv on May 15.

The real shock was the destruction of two launchers of the US Patriot anti-aircraft system in early March near Pokrovsk, in the Donbas region. The extremely expensive system, crucial for keeping Russian bombers at bay, was spotted by a Supercam drone and immediately destroyed by an Iskander ballistic missile strike while parked in the open alongside a road. It had shot down several enemy bombers in the preceding weeks, which is why Russian drones were hunting it down with every last bit of resolve.

You have 66.4% of this article left to read. The rest is for subscribers only.