The threat was demonstrated last November, when operatives believed to be part of al-Qaeda tried to shoot down a plane full of Israeli tourists as it took off from an international airport in Kenya.
You may remember that about 3 years ago, some Islamist extremist kidnapped 16 Western tourists in Yemen and four of those tourists were then killed in a shoot-out.
Last year Macau's security chief, Manuel Monge, blithely reassured tourists worried about being caught in gangland shoot-outs that the hitmen never missed their mark.