China is attacking Japan for their possession of the Senkaku islands, claiming that the islands in question are actually part of Taiwan - which China also claims, but doesn't control.
In addition, China is trying to pressure Japan by also claiming Okinawa.
Rather than achieving their goals, this incredibly dubious claim over an island that has been a Japanese possession since 1879, is inhabited not by Chinese, but by Japanese, and which was not actually ever controlled by China - the kingdom of the Ryukyus, while a Chinese vassal, was an independent country, has just made the Japanese even firmer than before.
Given how numerous Chinese territorial disputes with other countries are, and how much tension is generated over its unjustified claims, I'm thinking that someone is going to go to war with the PRC before too long.
The Middle East and Southeast Asia are the two biggest world hot spots at the moment. The middle east because of Iran and Syria, Southeast Asia because of China and North Korea. The next war that the US gets involved in is going to be in one of those four countries, barring an unforeseen change in the situation.