> But lasers can be detected with the right equipment (think the classic "laser through fog" but happening to plain air molecules)
You are assuming that the only source emitting at the specific wavelength is the laser you are targeting. This is not how it would work, the side using laser comms would also fly decoy drones that bathe the sky in the same wavelength as the comms channel.
This is also key part of how LPI radars on stealth aircraft work. Yes, in a spherical cow in vacuum environment you can in principle always trace a radar signal back to its source. But add a whole bunch MALDs radiating on the same band as the radars, and suddenly it becomes impossible to pinpoint the sources.
You are assuming that the only source emitting at the specific wavelength is the laser you are targeting. This is not how it would work, the side using laser comms would also fly decoy drones that bathe the sky in the same wavelength as the comms channel.
This is also key part of how LPI radars on stealth aircraft work. Yes, in a spherical cow in vacuum environment you can in principle always trace a radar signal back to its source. But add a whole bunch MALDs radiating on the same band as the radars, and suddenly it becomes impossible to pinpoint the sources.