They have a centuries-old blood feud, they'll fight over anything... and while the islands are not important, it is the massive oil and natural gas fields beneath them that matter... and Japan is (wisely) flexing as well, and hopefully they use the coming war as an excuse to change their Constitution. 60+ years of letting the US be their primary defense is enough. Let them take on China without our boys being put in the middle.
I think you both are confusing the new East China Sea dispute with the old South China Sea dispute, which is over control of the oil rich area surrounding the Spratly Islands, near the Philippines. However, you are both correct, China is flexing its muscles in response to a weakening USA as part of bh0’s mission of ‘fundamental transformation.’
See also the links in my earlier posts, #12 and #17