There could be trouble ahead.

[Jimbuna]

Will the US back SK up?

South Korea has announced it is expanding its air defence zone, which will now partially overlap with a similar zone announced by China.

The two zones will now both include a rock claimed by both countries and controlled by South Korea.

The defence ministry said it would co-ordinate with "related countries".

China announced a new Air Defence Identification Zone (ADIZ) last month, in a move that raised regional tensions.

Both countries' zones will cover the airspace above a rock called Ieodo by South Korea and Suyan by China, which is claimed by both countries.

http://www.bbc.co.uk/news/world-asia-25288268