Analysis: Russia breaks into Kostiantynivka, opening battle for Donbas fortress belt

Amid a wave of positive headlines about Russian refineries in flames and logistics crippled, the battle for the legendary "fortress belt" of Ukraine's Donbas region has begun in earnest, with Russian forces breaking into the city of Kostiantynivka in Donetsk Oblast and steadily overrunning the urban area. As the summer campaign opens up, Russian forces are bucking the trend of offensive stagnation across the rest of the front line and making real headway into the heart of Ukrainian-controlled D