South Korean Aegis destroyer Yulgok YiYi patrols the waters around Socotra Rock, south of Jeju Island, on Dec. 2. Photograph by Yonhap via EPA
South Korean Aegis destroyer Yulgok YiYi patrols the waters around Socotra Rock, south of Jeju Island, on Dec. 2. Photograph by Yonhap via EPA

All the drama surrounding China’s declaration of a vast “air-defense identification zone” off its shores centers on the disputed islands known as the Senkaku by Japan, which administers them, and the Diaoyu by China, which challenges Tokyo’s claim. The new zone encompasses the airspace over the islands: Beijing wants any planes in the area to identify themselves beforehand or face unspecified, possibly military, action. Japan scoffs at this demand, as does the U.S., which has accused China of unilaterally trying to alter the status quo by threat of force.

The issue dominated U.S. Vice President Joe Biden’s visit to Tokyo today -- and will do the same when he travels to Beijing tomorrow. The Japanese have been pushing the U.S. -- which has recommended that American airlines respect China’s rules even if the U.S. military will not -- to take an even tougher stand against Beijing. If he really wants to undercut China, though, Japanese Prime Minister Shinzo Abe should be focusing on another island entirely.

Well, not an island exactly. Socotra Rock is a submerged rock feature sitting 15 feet below the surface of the East China Sea. The nearest actual territory -- less than 100 miles to the north -- belongs to South Korea, which calls the rock Ieodo and has built a towering helipad and research station on top of it to reinforce its claim. China, which also claims the feature (which it calls Suyan Rock), has extended its air-defense zone to cover it as well.

Outraged commentators in Seoul have called on the government to extend its own air-defense zone into the area -- something that wasn’t considered necessary when the zone was drawn (by the U.S. Air Force) in 1951. In fact, until now the only defense zone that included the airspace above Socotra Rock belonged to Japan, which has made no claim on the feature whatsoever.

That last detail gives Abe an opening, as Rand Corp. analyst Scott Harold points out. The prime minister could score an easy PR coup by offering to redraw Japan’s air-defense area, in close consultation with Seoul. In effect, Japan would cede the airspace over Socotra to South Korea to monitor. Abe could even earn a few brownie points by publicly calling the rock Ieodo -- an emotional issue for hardcore Korean nationalists -- and offering to collaborate in the marine research taking place there.

Such a move would accomplish two critical goals. For one thing, it would underscore exactly what China did wrong in unilaterally declaring its defense zone. Beijing is right that 20 other nations -- including its two neighbors and the U.S. -- have established their own such zones. But in doing so, none of them tried to restrict airspace claimed by another country. Where zones butted up next to one another, as in North America, the countries involved hashed out the boundaries together. China’s zone is hardly so comradely.

A show of cooperativeness here could also help thaw relations between Japan and South Korea, which have gone into a deep freeze. In recent weeks South Korean President Park Geun Hye has flatly declared that she sees no point in even sitting down to talk with Abe, whom she accuses of trying to whitewash Japan’s wartime record. U.S. officials have fretted that Park, who received a rock star’s welcome when she visited Beijing in June, was drifting closer to China than to fellow U.S. ally Japan.

Chinese officials clearly recognize that they’ve blundered by nipping off the airspace over Socotra Rock. They vow to resolve any issues with South Korea through “friendly consultations and negotiations.” But Beijing can’t afford to back down on the boundaries of its zone, not least because of raging nationalist sentiment at home.

Japan can and should. Shrinking its own air-defense zone a bit wouldn’t materially threaten the country’s security or its claim over the Senkaku/Diaoyu. Even if South Korean officials -- some of whom have started to make friendlier noises about Japan in the last few days -- don’t immediately respond, Abe would at least earn credit with the U.S. If Seoul embraces the idea, all three nations would be able to present a stronger, more united front against China.

How to exploit that solidarity is a separate issue. In Tokyo, Biden said the U.S. was “deeply concerned” about China’s recent move but did not call for the zone's outright rollback, knowing that would be an impossible demand. The best one can probably hope for is that China quietly does not enforce the zone against Japanese, Korean and U.S. military planes that fly through without identifying themselves. That will only work, of course, if the three allies don’t loudly publicize their defiance and China’s lack of response. Abe should remember that some grand gestures are worth making -- and some are not.

(Nisid Hajari is a member of the Bloomberg View editorial board. Follow him on Twitter.)