VIV, Ukraine (AP) — Russia launched its long-feared, full-scale offensive to take control of Ukraine's east on Monday, attacking along a broad front over 300 miles (480 kilometers) long, Ukrainian officials said in what marked the opening of a new and potentially climactic phase of the war.“The Russian troops have begun the battle for the Donbas," Ukrainian President Volodymyr Zelenskyy announced in a video address. He said a "significant part of the entire Russian army is now concentrated on this offensive.”The Donbas is Ukraine’s mostly Russian-speaking industrial heartland in the east, where Moscow-backed separatists have been fighting Ukrainian forces for...