The HQ-9 antiship missile emplacements by the Chinese are upping the ante in the South China Sea's tensions. Pictures and video are here. China has defended its placement of the missiles now.
The clashes of China and Indonesia are looked at here.
The positions of Australia and China with regards to the South China Sea are explored here.
The US has stated the air strips made by the Chinese on their reclaimed islands are definitely intended for military aircraft.
The Philippines is considering purchasing submarines due to the tensions in the South China Sea.