(Reuters) – Ukraine mobilized for war on Sunday and Washington threatened to isolate Russia economically after President Vladimir Putin declared he had the right to invade his neighbor in Moscow’s biggest confrontation with the West since the Cold War. “This is not a threat: this is actually the declaration of war to my country,” Ukrainian Prime Minister Arseny Yatseniuk said in English. Yatsenuik heads a pro-Western government that took power in the former Soviet republic when […]