Somebody in Manila is now drafting a reply to a Chinese charge that the Philippine aircraft was the intruder, while the Philippine account describes a PLA aircraft that came too close. Both documents concern one encounter over the South China Sea, and each is written to be quoted back at the other.

The vocabulary is chosen with care. Manila says "unsafe," a word that belongs to aviation practice and places the fault in how the PLA pilot flew. Beijing says "airspace," a word that belongs to sovereignty and places the fault in where the Philippine aircraft was. Neither word can be answered with the other's. A safety complaint does not concede the airspace, and a sovereignty claim does not address the separation distance, so the two ministries can file past each other indefinitely, or, more precisely, for as long as the paper is useful to both.

It has been useful before. On 10 September we wrote that a leaked diplomatic note had moved the dispute from patrol boats to paper, and that paper is what carries into any future arbitration. Nine days later a ramming incident put the Philippine bond book on notice. Our flashpoint map has logged 25 moves in the South China Sea since 6 September, the latest on 4 October, and the aircraft encounter adds another dated entry for each side.

The encounter itself is less consequential than the calendar around it. The Australian reports the marathon ASEAN talks on the sea are nearing their end, and whatever text emerges will be read against two freshly filed accounts of the same sky. A drafting officer in any ASEAN capital now has Manila's word, "unsafe," and Beijing's word, "airspace," on the desk beside the draft.

Regional bond desks price Manila off exactly this paper. The next entry will be whichever government answers the other's note first, and the talks give that reply a deadline.