It all boils down to how you write the item.

Check on this:

http://www.straitstimes.com/world/united-states/chinese-us-aircraft-in-unsafe-encounter-over-south-china-sea-us-pacific-command

The stat blame is on the Chinese plane. However the US plane must have flown to the point 300 m from the Chinese plane just as the Chinese plane flew to the point 300 m from the US plane. So:

WHO WAS FLYING IN AN UNSAFE WAY?

This close contact heightened tensions. 

The question is which of the parties, the US or China immediately tensed up with tension.

As far as I can see, there is no record in the Peoples Daily or Xinhua of any notice that the Chinese were tensed up about the meeting of these two planes in the sky.

And who wrote about heightened tensions? Well it was the Pentagon.

If the US spy plane was hit and had to do an emergency landing, where would it have to land?

Well, you got the answer have you not?

It would have to be on one of the airstrips that China has built on one of the atolls in the South China Sea. The consequences could be WW III . . . or not!