LONDON: Britain"s security relationship with its European allies was being galvanized by common problems such as dealing with militant fighters and brides returning to Europe after the collapse of Daesh"s "caliphate" in Syria and Iraq, the chief of Britain"s foreign intelligence service said on Friday. "We are very concerned about this because all experience tells us that once someone has put themselves in that sort of position they are likely to have acquired the skills and connections that make them potentially very dangerous," Alex Younger, chief of the Secret Intelligence Service, or MI6, said. "The reality is that so far, it has been a completely manageable problem," he added. "I can"t predict accurately what will happen in future, but it"s a very complex environment." Daesh has morphed and is proving "adept at inspiring attacks rather than directing them", he said. "Al-Qaeda, which has always been in a rivalry, and almost zero sum relationship with Daesh, has, I think, undergone a certain resurgence as a result of the degradation of Daesh," he added. "It is definitely not down and out."