These are fiber optic threads left by FPV drones, which are controlled via optics.
Right now, they are the most effective way to precisely target objectives, as they are immune to electronic warfare (EW) measures. The threads hanging from the trees at the front line demonstrate just how actively such drones are being used right now.
Who will clean up the fiber optics later? No one is thinking about that yet. But the threads are so thin and incredibly strong, it’ll be a real hassle to remove.
