The South China Sea, a major transit area of international maritime traffic, is the scene of territorial and maritime claims expressed by the riparian states, including China but also Vietnam, the Philippines, Malaysia, Brunei, and Taiwan, and now represents one of the main stumbling blocks in the US-China bilateral relationship. Between October 2015 and mid-May 2016, a series of initiatives taken unilaterally by China on one side and the US on the other have greatly exacerbated the latent confrontation of the two powers in this maritime space.Chinese initiatives have essentially consisted of fitting out the Paracel Islands and some recently reclaimed reefs of the Spratly archipelago with transport infrastructure. To this end, the Chinese Ministry of Transport has installed three lighthouses on the Spratly Islands: two on Cuarteron and South Johnson reefs on 9 October 2015(1)and a third on Subi Reef on 6 April 2016.(2)On 2 January 2016, the spokeswoman for the Chinese Ministry of Foreign Affairs, Hua Chunying, confirmed completion of construction of an aerodrome on Fiery Cross Reef, which US satellite photos already showed in 2014.(3) This confirmation was followed on 6 January by the organisation of two civilian flight tests - one operated by China Southern Airlines and the other by Hainan Airlines - between the airport of Haikou, the provincial capital of Hainan, and the new Fiery Cross airfield.(4) Both tests may indicate future exploitation of this line on the heels of what the Chinese authorities already planned to do in the Paracel Islands.(5) Finally, other actions such as the deployment of aircraft missile launchers on Woody Island on February 2016 (6) and anti-ship missiles in March(7) seem to confirm the militarisation of the Paracels while leaving some doubt as to the establishment of a similar process in the Spratlys, which could lead, according to some observers, to the delimitation of an air defence identification zone in the South China Sea. (8)These initiatives, which will probably be followed by others in the coming weeks and months, are the undisputed testimony of an increasingly firm will from China to increase its presence in the South China Sea in order to more effectively monitor this space and impose itself as the dominant power. China thus materialises a historically self-proclaimed sovereignty.At the same time, Washington has allowed the US Navy to conduct three Freedom of Navigation Operations (FONOP). Three guided missile destroyers, the USS Lassen, on 27 October 2015, the USS Curtis Wilbur, on 30 January 2016, and the USS William P. Lawrence, on 10 May 2016, have respectively sailed within 12 nautical miles of Subi Reef, Triton Island, and Fiery Cross Reef, all claimed and occupied by China. (9)The fact that the two countries answer each other through these actions is obvious. The deployment of missile launchers on Woody Island is clearly a response to the passage of the USS Curtis Wilbur near Triton Island, all the more so given that China undertook this deployment during the US-ASEAN special leaders' summit in Sunnylands, California, in the course of which Barack Obama reiterated that the US would continue to fly, sail and operate wherever international law allows. The summit's joint statement, without clearly mentioning Chinese initiatives in the South China Sea, included calls for respecting freedom of and overflight in the maritime areas as well as non-militarization and self-restraint in the conduct of activities.(10)In fact, a major concern in Washington is that this assertion of Chinese presence in the South China Sea will eventually threaten freedom of navigation and in the process, American strategic and economic interests. This concern is partly fuelled by China's official position regarding certain articles and clauses of the United Nations Convention on the Law of the Sea (UNCLOS) relating to the right of innocent passage through the territorial sea or in the conduct of activities by foreign military ships and aircraft in the exclusive economic zone (EEZ) of the coastal state. …