Britain joins Syria air war; Putin vows more sanctions on Turkey

By Guy Faulconbridge and Andrew Osborn LONDON/MOSCOW (Reuters) - Britain joined U.S.-led air strikes against Islamic State in Syria on Thursday, but Vladimir Putin issued bitter new denunciations of Turkey for shooting down a Russian plane, demonstrating the limits to international solidarity. British Tornado jets took off from the Royal Air Force base at Akrotiri in Cyprus before dawn, hours after parliament in London voted 397-223 to support Prime Minister David Cameron's plan to extend air st