Keir Giles, a Russia analyst for the Chatham House think tank, says that Russia's stated aim of conquering Ukraine's eastern provinces may be flexible, due to the government's control of domestic news it can present different outcomes as a victory, possibly in time for the May 9th commemoration of victory in World War 2. On unconfirmed reports of a chemical weapons attack by Russia in Mariupol, Giles says it's possible such an attack could be a test to gauge Western reaction. SOUNDBITES