It is a mark of the secrecy that has long surrounded China’s military establishment that the hulking defence headquarters on Beijing’s main avenue is not identified by a single sign and is omitted entirely from many municipal maps.

Yet as the People’s Liberation Army emerges as one of the region’s most potent forces, defence officials are making unprecedented efforts to present a more open and positive face to the outside world, from taking part in international peacekeeping operations to loosening curbs on contacts with journalists.