I wouldn't be surprised if the PRC "military capable" airfields in the Spratlys, even without the issues of radars and missile batteries, are deemed a credible threat to US forces at Antonio Bautista.
One factor might be the desire of Malaysia and Indonesia to maintain freedom of movement in their dealings with China despite being berated by pivoteers for spinelessness (the US embassy in Jakarta arranged a publicized conference call by core pivoteer from the US Naval War College, Peter Dutton of “Be Nice and Share” fame, to give advice on dealing with the PRC that Indonesia, which stakes its regional identity on an independent honest broker/emerging power basis, perhaps did not appreciate).
Another factor may have been a generous supply of carrots from the PRC, anxious to keep the ASEAN countries divided or at least equivocal as PRC defeat on the UNCLOS arbitration looms.
The immediate response to the Indonesian incident was virtual panic at the PRC Ministry of Foreign Affairs, followed by a deep public silence.
A think tank with PRC affiliations in the United States (yes, they do exist) that counts the public face of PRC South China Sea strategy, Wu Shicun, as its adviser, published a piece in Global Times that posited the validity of “historical fishing rights” that override UNCLOS and would therefore survive a negative ruling on the Nine Dash Line.
The kicker was that the rights would be “non-exclusive” in other words, the PRC could get a share of fishing rights in somebody else’s EEZ, for instance at Scarborough Shoal.
Given the welter of overlapping claims and contention (in addition to its dustup with the PRC, Indonesia has been not only seizing but also blowing up over a hundred seventy fishing boats from Malaysia, Vietnam, Papua New Guinea, Taiwan, etc. to enforce its maritime domain), this might even be a form of consensual divvying up that all SCS claimants might like.
However, the Philippines window to avail itself of the PRC’s offer is rapidly closing as US policy drives its security policy and ramshackle presidential politics.
And I think the US would be loath to see expressions of bilateral comity around the South China Sea that would undercut its thesis that a united confrontational stance backed by US muscle is the best way to solve the complex problems in the SCS.
One sign that the DoD wants to draw a hard clear line with the US and the Asian democracies on one hand and the PRC on the other was Carter’s decision to snub the PRC and cancel his previously planned visit as part of his India/Philippines swing.
Carter’s Council on Foreign Relations speech on April 8 was, in fact, rather embarrassing in its over-the-top India adoration and cheerleading for defense co-production agreements, perhaps a sign that the bazaar is open and now, when the US needs public support for its PRC policy, is the time for India to dive in and scoop up the best deals on US defense cooperation.
The US wants the anti-PRC alliance to go to the next level, not wobble.
So it will be interesting to see what other provocations, in addition to visit cancellations, taunting helicopter photos, HIMARS, and more aggressive FONOPs are in the offing...and whether PRC fishery appeasement is allowed to gain any traction.