A security expert has warned a terror attack on the scale of last week's strikes in the United States could happen in Hong Kong. Aviation security expert Ian Gilchrist said the SAR and other major Asian centres had the 'ingredients' for terrorists to mount an attack. For terrorism to occur, a country needed to have desirable targets, a respect for individual rights that made law enforcement more difficult and a diverse society into which attackers could blend. Mr Gilchrist, director of Asian operations for Hill and Associates, is a former head of airport security in Hong Kong and worked for the International Civil Aviation Authority for nine years. He said the answer to many people's question on whether a similar attack could occur in the SAR was a 'resounding yes'. Speaking during a panel discussion luncheon at the Foreign Correspondents' Club, Mr Gilchrist said he anticipated draconian and dramatic changes to aircraft security. Potential counter-terrorist strategies examined by international authorities in the past - but not implemented - included reinforcing cockpit doors on aircraft, gas to knock out all people in the passenger section in case of an attack and even pop-up hypodermic needles hidden in the seats. Mr Gilchrist said some staff who were expected to be strong in emergencies turned out to be unsuitable in drills. He also said chief executives were not always the best crisis managers. Factors businesses should examine included security of their premises, travelling executives' security, contingency plans and the formation of crisis-management teams. A terrorism expert, former FBI special agent and regional managing director of Kroll Associates (Asia), Harry Godfrey, said Hong Kong had been a safe location for many years. 'I don't see anything sufficient that would indicate there's a particularly unusual threat to Hong Kong,' he said.