WHY IS CHINA BUILDING BRIDGES???

Dotted with small islands, reefs and shoals, the South China Sea is a home to a messy territorial dispute that pits multiple countries against each other

China's nine-dash line claimed territorial waters that extend hundreds of miles to the south and east of its island province of Hainan -- abut its neighbors' claims and, in some cases, encroach upon them.

Tensions have ratcheted up as China has reclaimed some 2,000 acres of land in a massive dredging operation, turning sandbars into islands equipped with airfields, ports and lighthouses. 

On Tuesday, China said it warned and tracked the U.S.S. Lassen, a destroyer, as it came close to five of its artificial islands in the South China Sea's contested waters.

Cui Tiankai, Chinese ambassador ttold the media on  Tuesday that the U.S. patrol was "a very serious provocation, politically and militarily."