COULD PUTIN LOSE? “Pro-Russian rebels abandoned Sloviansk as government troops retook the eastern Ukraine city after a night of fierce fighting and barrages of mortar fire, the country’s president and a spokesman for the rebels said Saturday. President Petro Poroshenko said in a statement that government troops took Sloviansk, a city of about 129,000 that has been a center of the fighting between Kiev’s troops and the pro-Russian insurgents in Donetsk. Poroshenko commanded the armed forces to raise the Ukrainian flag over the city, which had been under rebel control since April 12 when they seized the city’s administrative and police buildings.” Or will he send in regular troops?