After extensive dredging operations and the conversion of reefy shoals into artificial islands, China has made little secret of its intention to fortify its claim to disputed portions of the south China Sea. Now, if intelligence briefing and satellite imagery provided by a United States think tank are to be believed, Beijing has added sophisticated weaponry and missile systems to the disputed islands, giving an ominous meaning indeed to the very use of the word ‘fortify’.

The Asia Maritime Transparency Initiative at the Centre for Strategic and International Studies said its findings come despite statements by the Chinese leadership that Beijing has no intention to militarise the islands in the strategic trade route, where territory is claimed by several countries. The agency said it had been tracking construction and was able to identify surface-to-surface and surface-to-air missile systems as well as heavy defensive weaponry.

The Fiery Cross, Mischief and Subi reefs in the Spratly Islands have been converted into full-scale islands with functioning airstrips — a clear intent that Beijing has laid claim to the territory, regardless of an international arbitration ruling from The Hague and the counter-claims by the Philippines, Vietnam and others. Outgoing US President Barack Obama had sent a missile frigate through the disputed waters and followed up days later with the overflight by two B52 bombers — a clear message to Beijing that Washington was prepared to act on the accepted principle of free navigation and passage.

Given US President-elect Donald Trump’s decision to pick a spat with China over Taiwan even before he takes office, it’s hard to know just how this will unfold. Add to that another unpredictable character in the form of Philippines President Rodrigo Duterte and the South China Sea can go south any moment. Calmer heads must prevail.