Unilateral air defence zones add to tensions

US Vice-President Joe Biden stopped short of calling for China to dismantle its new air defence identification zone (ADIZ) during his trip to Beijing last week. But it is clear from subsequent news reports that the air defence zone was discussed during the five-hour meeting with Chinese President Xi Jinping. In any event, the United States has made clear its own position on the issue by flying two B-52 bombers through the zone without seeking China's permission.

Beijing has taken comfort from the fact that since the announcement of its East China Sea ADIZ, a majority of civil aviation companies with their air routes traversing the area have reported flight plans to China's civil aviation department. China's air force says it will conduct regular air patrols covering its zone and, more ominously, warned that combat aircraft would "strengthen monitoring"…