根据《每日电讯报》的报道，俄罗斯根据“三线制”原则，已经构建了世界上最强大的防御线，并设立了不同级别的防御工事。最新的卫星图像显示，过去六个月里，俄罗斯建立了一套复杂的防御网络，包括众多的雷区、反坦克壕沟和战壕。在某些方向上，这些防御工事甚至可以超过30公里。英国情报机构形容，俄罗斯加强其防御位置的努力是他们所见过的“最大规模的军事防御系统之一”。值得注意的是，战争初期，乌克兰在南部并没有与俄罗斯相似的防御工事区域。 Russia has built the most powerful line of defense in the world according to the "three-line system" with different levels of fortifications - The Telegraph New satellite imagery shows the complex network of Russian defenses that has been built up over the past six months: many minefields, anti-tank ditches and trenches, which in some directions can exceed 30 km. British intelligence described Russia's efforts to strengthen its positions as "one of the largest systems of military defenses they have ever seen." It is noted that Ukraine at the beginning of the war did not have areas of fortifications in the South that closely resembled what the Russians did.