Russia's War Against UkraineReuters: ‘Russian aggression greatest threat to Ukraine’ – John Kerry in KyivBy Reuters. Published Feb. 6, 2015 at 10:36 pm Ukrainian President Petro Poroshenko (R) and US Secretary of State John Kerry shake hands after their press conference in Kiev on February 5, 2015. Photo by Volodymyr PetrovThe US Secretary of State visiting Kyiv has said that Russian aggression is the greatest threat to Ukraine. Read more here