The Japanese and U.S. governments on Tuesday disclosed details of a technical report on a replacement facility for U.S. Marine Corps Air Station Futenma, now set in a crowded residential area of Ginowan in the central part of Okinawa Island. A 2006 Japan-U.S. accord called for building two, V-shaped runways at Camp Schwab in Henoko, a less densely populated area in Nago in the northern part of the island, and in adjacent waters. The report presents two options — either V-shaped runways or a single runway. Under either plan the runway portion would be 1,800 meters.

It was the Japanese government that included the single runway plan, which would reclaim some 40 hectares less, or 25 percent less sea area than the V-shaped option, and have a smaller impact on the local marine environment — a habitat for dugongs — in order to appease Okinawan people over the relocation of the Futenma functions. But as long as the new facility is built within Okinawa Prefecture, local opposition is not likely to wane.

The United States appears determined to stick to the V-shaped option. But a problem has surfaced during recent negotiations. The U.S. had explained that the V-shape option would enable aircraft using a visual flight path to avoid flying over local residential areas. But the visual flight path of the V-22 Osprey vertical takeoff and landing aircraft now described by the U.S. would be closer to land areas than the Okinawan side was led to believe by the Japanese government. Fearing that this detail would infuriate Okinawans, the Japanese government did not mention the flight path in question in the report — as if it were trying to hide this important information.