A massive network of trenches, traps, and other barriers has recently appeared close to one of the war's worst front lines in Ukraine.
Russia constructed the defenses to impede Ukraine's attempts to seize Popasna, a town they had taken in May. According to a New York Times examination of satellite radar data, they make up a very small portion of a vast Russian defensive network that is spanning the entire country of Ukraine.
These facilities might allow Russia valuable time to gather and train more troops in order to recover the initiative in the conflict. Ukraine, though, might put Russia's capacity to maintain these positions over the winter to the test.
Ukraine is no stranger to trenches. The conflict in eastern Ukraine over the Donbas region has long included trench warfare. Russian forces are undertaking a fierce campaign to drive Ukrainian forces from the city of Bakhmut, and Ukrainian soldiers are fighting from their own trenches on their side of the line close to Popasna.
However, the speed and size of Russian construction over the last few months is unparalleled.
The fortifications demonstrate the Russian military's efforts to fortify stronger, more secure locations to stave off Ukrainian pressure, frequently with the aid of rivers and other natural barriers.
Last month, Ukraine pushed Russian forces across the Dnieper River and reclaimed a sizable portion of the southern area, including Kherson, the regional capital. Russia has erected a massive network of defensive barriers south of the river to prevent Ukraine from crossing it, which acts as a natural barrier.
The defenses include deep pits called tank traps and miles-long rows of concrete pyramids known as dragon's teeth. Both aim to sluggish Ukrainian vehicles and push them into predetermined areas where Russian forces can fire upon them.
Additionally, Russia is constructing miles of trenches and pillboxes, which are modest buildings from which its soldiers can fire.
According to Philip Wasielewski, a fellow at the Foreign Policy Research Institute, the positions are only valuable if there is a systematic Russian withdrawal, which is one of the trickiest tactical operations to execute.
"There is no assurance that the forces will reach those defenses. Or, rather than just continuing to run once they arrive, Wasielewski suggested. Unless they are defended by disciplined, motivated soldiers who are assisted by artillery, mobile reserves, and logistics, these are merely holes in the ground.