Venturer, It isn’t only about ‘some worthless islands’ but control of the sea and air lanes that cross the East China Sea. this is a huge area between China, Korea, Japan, and Taiwan. It is an area of 482,000 square miles. Here is the area in dispute: http://en.wikipedia.org/wiki/East_China_Sea
It is also the claiming of ownership of an area that is beyond the internationally agreed 12 mile limit. Imagine if the USA said, “We own the entire Gulf of Mexico and countries could not send aircraft or ships into its area without out our permission.
And tie this into their claims of ownership of the Spratly Islands in the South China Sea. a group of islands closer to the Philippines than China.
This is an important and dangerous confrontation. If China shoots down anything, it could result in war.