(August 12, 2025)

– The fortress belt is made up of four large cities and several towns and settlements that run north to south along the H-20 Kostyantynivka-Slovyansk highway, with a total pre-war population of over 380,537 people. The belt is 50 kilometers long (roughly 31 miles, about the distance between Washington, D.C., and Baltimore, Maryland).
– Ukraine has spent the last 11 years pouring time, money, and effort into reinforcing the fortress belt and establishing significant defense industrial and defensive infrastructure in and around these cities.
– Slovyansk and Kramatorsk form the northern half of the fortress belt and serve as significant logistics hubs for Ukrainian forces defending in Donetsk Oblast. Druzhkivka, Oleksiyevo-Druzhkivka, and Kostyantynivka serve as the southern half of the fortress belt.
– Ukrainian forces first began building up defensive positions in and around these cities after retaking them from pro-Russian proxy forces who attacked and seized Slovyansk, Kramatorsk, Druzhkivka, and Kostyantynivka in April 2014.
– Russia’s failure to seize Slovyansk in 2022 and ongoing struggles to envelop the fortress belt underscore the success of Ukraine’s long-term efforts to reinforce the fortress belt cities.