KYIV/DRUZHKIVKA, Ukraine—Ukrainian troops battled Russians street-to-street in the ruins of Sievierodonetsk on Tuesday, trying to hold onto gains from a counter-offensive that had reversed momentum in one of the bloodiest land battles of the war.
The fight for the small industrial city has emerged as a pivotal battle in eastern Ukraine, with Russia focusing its offensive might there in the hope of achieving one of its stated war aims—to fully capture surrounding Luhansk Province on behalf of separatist proxies.
After withdrawing from nearly all the city in the face of the Russian advance, Ukrainian forces staged a surprise counter-attack last week, driving the Russians from a swath of the city centre….