By Jonathan Landay RUSKA LOZOVA, Ukraine (Reuters) – While three of his men heaped dark soil into a chin-high berm to shield their trench, Ohor Obolenskiy gestured on Sunday across sun-dappled fields to a tree-clad ridge line sweeping the nearby horizon. “We can see the Russian positions from here and say, ‘Fuck you, Russians,’” the 35-year-old Ukrainian commander joshed in rough English, his grim face creasing into a wide grin. The amalgam of National Guard and volunteers he leads seized Ruska Lozova in fierce fighting on May 8, four days into a counteroffensive that has thwarted Russia’s bid…