There was a Sci-fi novel that had a very similar theme. I for get the title.
The novel is set in a future USA where the country has been split into two main factions, East and West, and some minor regional factions.
The East and West are constantly at war, with periods of ceasefires that don’t last more than a few months. Situation similar to the two Koreas.
One side, the weaker West, has developed a secret weapon that scares the hell out of the East. It has only been tested in a limited small battle and proved to be a game changer.
The East sets about to capture or destroy the weapon but doesn’t know where it is.
They forcibly recruit a former famous stage actor, Harry (I can’t remember his name) who is alcoholic and living his life as an itinerant farm worker harvesting produce in rural East America. At first he refuses but they threaten his family he has abandoned and he finally agrees to become their spy in the West.
They supply him with a travelling bus and mobile stage and a cast and crew of actors and a technician who all portray a gypsy-like group of actors that travel from place to place putting on plays for rural towns that have no access to urban entertainment. There is no Television or radio because of the war, and there are other groups who do the same thing, so they do not stand out as suspicious.
Harry eventually discovers that the other actors are just that, actors, who have no other jobs and are oblivious to the real reason they are there. The ‘technician’ is the East’s situation control commander who directs Harry and controls his actions to find out the location of this weapon when he’s mixing with the locals in between performances. He has a secret transmitter in the equipment van to communicate with the East’s HQ.
They travel from town to town putting on shows and Harry eventually hits on a lead to where the weapon is located, so they head there.
After a lot of skulduggery and various situations the weapon is finally located in an old church.
Harry falls in love (of course) with a local woman and he is convinced that the West are the good guys and the East are the bad guys.
There’s a big finale fight and Harry kills the technician /commander as the East’s military forces are on their way to bomb the town into oblivion.
It runs out that the secret weapon is a type of EMP device that works like a combination Radar/Laser beam.
Aircraft, tanks, vehicles, machines, anything with electronics will just stop working when hit by the beam’s energy.
Harry and his band of actors figure out how to use the weapon and use it to destroy the East’s advancing military armada.
Hundreds of Aircraft just fall out of the sky, vehicles just stop in their tracks dead. Munitions and targeting computers are dead. Nothing works.
This sounds like Zelenskyy’s source.........................
If you ever recall the title let me know. It sounds a little like Not This August meets The Man In The High Castle.