【明報專訊】THE LIGHTHOUSES China had built on two reefs in the South China Sea went on last week. That means China's reef facilities have been completed and will soon be brought into operation. According to UK and US media reports, to express strongly America's rejection of China's claim to sovereignty over some islands Beijing has built there by reclamation, the US Navy may send in two weeks its vessels within twelve nautical miles of them. Harry Harris, who heads the US Pacific Command, has said the military have made preparations for the operation and are only awaiting President Barack Obama's order. As Xi Jinping has just wrapped up his US visit and is to visit Vietnam and attend an annual Asia-Pacific Economic Cooperation (APEC) summit in the Philippines next month, the transpiration of the news shows the South China Sea question may well be a new hot spot of Sino-US conflict in the days to come.