Last time I asked who in your organization is allowed to play the enemy against your own system. This time the enemy did it for us — using our phone networks.
Ukrainian teams opening up downed Russian one-way drones keep finding the same parts list: a Raspberry Pi-class minicomputer, a webcam, USB modems — and SIM cards. Ukraine’s defence intelligence has documented how it works. The drone logs into the local LTE network like any other subscriber and streams its footage home through disposable Telegram bots. Some of the SIMs are Ukrainian. Some, pulled from drones downed in September 2025, were European — routes through Poland and Lithuania, planned months ahead, documented in plastic.
I stopped at that detail because it breaks the rule I have written about most often here: emit and you die. This drone emits constantly and survives. Among millions of phones, one more subscriber is not a signature. It hides on towers the defender maintains, on bandwidth the defender built, under tariffs the defender regulates.
And that last word is where it turns. The counter is not an interceptor. Ukraine has blocked roaming for suspicious SIM classes and is weighing passport checks for SIM sales — air defence conducted at the mobile-shop counter. Whether it holds is an open duel; Russia gets a vote. But the shape is instructive: a weapon that borrows your infrastructure hands you its weakest point, because access can be revoked by whoever owns it.
A century of air-defence thinking asks how to hit the incoming object. The SIM card asks a better question: what does the object depend on — and who signs its contract?
So, this letter’s question: which civilian infrastructure would your adversary’s cheapest weapon enrol in — and who holds the power to revoke its access? Reply if you know the answer for your own country. I suspect most of us don’t.
Since the last letter
The drone with a phone plan — the full note, with sources.
Further back in the notebook
The army that taught the lesson failed the exam — Zelenopillia, 2014: the original version of “emit and you die”, which this drone turns inside out.
The bicycles of Storskog — another case where the decisive lever was an administrative rule, not a sensor.
One thing worth reading
Jack Watling, Statecraft: The New Rules of Power in a Divided World (2026). Watling usually writes about close combat; here he steps back to the levers around the battlefield — economics, dual-use technology, chokepoints. Read it with the SIM card in mind: the chokepoint that matters next may be a licence, not a strait.
Next letter in two weeks. Reply if you disagree — that is what this is for.
Christoph