I was doing communications in military. For temporary networks, we used microwave links and they requires line of sight. The reason to use direct link is that missiles can be easily targeted to any radio source you can hear and take down the network.

Yeah, I was aware of this because of work with telecommunications in rural locations. Nobody is burying a cable over a mountain, that's too expensive and too much work. So instead, they'll setup microwave towers. Being on a mountain has the benefit that you are already in elevated locations that are easy to shoot a phone signal across the range.

It's worth noting that free space laser comms would also have this problem though: the atmosphere has dust, and any IR detector will see bloom and reflection of dust from a laser which will draw a straight line right back to the emitter.

Shoot a laser pointer at the receiver and there's a good chance you have jammed the thing.

how do you detect/find the receiver? thats seems to be a problem

I thought comms was two way.

so you have a laser and want to jam the comms channel. How do you find where the comms channel is, where is the receiver, where do you point your laser to jam enemy comms?

I agree it is not an easy task. But lasers can be detected with the right equipment (think the classic "laser through fog" but happening to plain air molecules), unit movements can be tracked and straight sight line is a significant logistical restriction.

But if they were only receiving. Well, that's going to be pretty hard to confirm and even if you "jam" it, then so what?

> 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.