The Chinese have come up with a new strategy for controlling vital sea lanes. Build islands and then put bases on them. They have, according to U.S. Pacific Fleet Commander Adm. Harry Harris, built “a ‘great wall of sand’ in contested waters near its shores … pumping sand onto live coral reefs — some of them submerged — and paving over them with concrete … [creating] over 4 square kilometers of artificial landmass.”
Mark Hensch of The Hill writes that:
The land reclamation projects are in areas also claimed by Vietnam, Taiwan and the Philippines, among others
But:
China claims sovereignty over the South China Sea, citing its historical role in the region. This has angered U.S. allies in the area with their own interests there.