This would be more like the border clashes China has had with the Soviets, India and Vietnam rather than WWII. I expect it wouldn't escalate to the level of the Korean War, since these would be air and naval clashes. It's a chance for the Chinese to blood their air and naval assets while giving us the opportunity to find out just how well they've copied our technology, and whether they've come up with creative variations we hadn't thought of. Once you look at the map at the BBC link, it's clear this is the kind of massive land grab by a great power that we thought had gone out of style after WWII. History isn't dead - it was just slumbering.
So if WW3 starts with China...do we have to pay them back?
Excellent assessment! Oh, crap...lol!