SNA (Tokyo) — Futenma Marine Corps Air Station in Ginowan, Okinawa, must close—on that much everyone agrees. But the insistence by the United States and the Japanese central government on building a replacement facility in another part of Okinawa is bitterly opposed by Okinawa’s people and prefectural government.

In dismissing their concerns, the US State Department employs a boilerplate argument stating that moving to a new airfield offshore Camp Schwab in the Henoko district of Nago city “is the only solution that addresses operational, political, financial, and strategic concerns, and avoids the continued use of Marine Corps Air Station Futenma.” This assertion seems to satisfy most mainstream media in Japan and the United States. Put simply, the media does not ask the State Department to defend this assertion based on a factual argument.

Futenma is home to Marine Aircraft Group 36 (MAG-36), which provides air transport for the ground troops of the 31st Marine Expeditionary Unit based at Camp Hansen, also in Okinawa. So to argue that it’s strategically indispensable that Futenma’s replacement be in Okinawa is to argue—at minimum—that the 31st Marine Expeditionary Unit has a strategically critical mission that it could not perform if it were based anywhere else.

Proponents of the Marines’ presence in Okinawa insist that it hits a geographical sweet spot. As Marine Lieutenant General Lawrence Nicholson put it, “We have China, North Korea, Russia, and the violent extremism that is occurring today in Mindanao of the Philippines. The location here, a couple hundred miles south of Japan, puts us centrally located to be able to respond quickly.”

In support of such claims, the Congressional Research Service produced the following map:

One could fault the Congressional Research Service’s selection of cities, but if proximity to Taipei, Beijing, Pyongyang, Seoul, and Tokyo is the standard, their combined distance from Okinawa is some 3610 nautical miles. Just by way of example, the combined distance to those cities from the Marine airbase in Iwakuni, Yamaguchi Prefecture, is 24% shorter. So one flaw in the “centrally located” argument is that it doesn’t necessarily point to Okinawa.

Numerous experts reject the notion that having Marines in Okinawa is strategically critical:

—“There is nothing special about the geographical position of Okinawa.” (Former US Defense Secretary William Perry)

—“[A]lthough the US Marine Corps’ presence in the region is extremely important, its particular location in the western Pacific is less critical, as long as training facilities and infrastructure are adequate.” (Eric Heginbotham, Ely Ratner, and Richard J. Samuels, writing in Foreign Affairs)

—“Even if the Marine Corps left Okinawa, if the Air Force and the Navy were to stay in Kadena and mainland Japan, there would be no change in deterrence.” (Barry Posen, director of MIT’s Security Studies Program)

The 31st Marine Expeditionary Unit, in particular, is the only one of seven Marine Expeditionary Units based outside the United States. If the others can deploy from California or North Carolina, it’s unclear why the 31st cannot.

If Okinawa’s location is so crucial, shouldn’t the 31st Marine Expeditionary Unit stay there, always at the ready for a regional military crisis? In fact, the unit deployed to Iraq from September 2004 to March 2005 and has engaged in natural disaster responses in Indonesia and Myanmar. Beyond such missions, the unit regularly spends roughly six months a year visiting countries like Australia for joint training exercises. So if a crisis on the Korean Peninsula breaks out, there’s a good chance that it won’t even be in Okinawa.

Of the Marines’ air-ground task forces, Marine Expeditionary Units are the smallest, with just 2,200 troops. In comparison, for example, to the 23,000 US troops in South Korea, the 31st Marine Expeditionary Unit’s size would limit its role in any contingency, except perhaps for one involving the Senkakus.

If they’re in Okinawa to defend Japan’s disputed control over uninhabited islets in the East China Sea, proponents should say so. As the Congressional Research Service notes, “The potential role of US Marines in defending and/or retaking uninhabited islands from a hypothetical invasion force is unclear.” In any case, wouldn’t such a task fall more appropriately to Japan’s own version of the Marines, scheduled to be inaugurated later this year?

As for countering Chinese aggression more broadly, Posen avows that he “cannot see what role the Marine Corps might play in military actions that are likely to take place in the context of Japan-China or China-Taiwan relations.”

Providing air transport for a unit of minor strategic importance that needn’t be in Okinawa, Futenma is, as former ambassador to Japan Michael Armacost declares, not an essential base.

Ultimately, no base is absolutely necessary, explained former Pentagon official Morton Halperin: “If you ask the military about any base which they now have, they will tell you ‘it is necessary.’” Instead, he says, “the question to ask is, what are the functions that you perform on the Marine base in Okinawa, and for each one of those functions, explain how you would do it next best if you lost the base on Okinawa.” As for Henoko, “I think we should have long since given up the notion of having a new Marine base on Okinawa, and paid whatever price—and I believe the price would be zero—but pay whatever price we have to pay in degradation or increased cost, to do the same function someplace else.”

With its colossal budget, the Pentagon can hardly plead poverty in rejecting alternatives, and it’s not as if none are available.

In 2011, three US senators, describing the Henoko plan as “unrealistic, unworkable, and unaffordable,” suggested moving Futenma’s assets to Kadena Air Force base, also in Okinawa. Akikazu Hashimoto and Mike Mochizuki propose that MAG-36 move to Kyushu or elsewhere in mainland Japan, transporting the 31st Marine Expeditionary Unit out of a heliport inside Camp Schwab. Elements of these proposals might meet with objections in Okinawa, but Mochizuki and Hashimoto’s idea at least “avoids the negative environmental consequences of the landfill project” in Henoko’s Oura Bay.

And while these proposals would leave the 31st Marine Expeditionary Unit in Okinawa, a detailed recommendation from the Japanese think tank New Diplomacy Initiative goes further, urging that “just as the I MEF [Marine Expeditionary Force] deploys an Marine Expeditionary Unit from California across the Pacific and into the Indian Ocean, the 31st Marine Expeditionary Unit could similarly be deployed from Hawaii or the continental United States.”

In inserting the word “political” into its rationale for Henoko as the only way to close Futenma while addressing “operational, political, financial and strategic concerns,” the State Department inadvertently revealed the overriding consideration. Henoko indeed appeared to answer Tokyo and Washington’s political concerns. In 2014, Japan’s defense minister justified US forces’ heavy concentration in Okinawa by saying, in Gavan McCormack’s paraphrase, “that no other district in Japan would have them.”

The Abe administration fears the political fallout from a move to the mainland, and Washington is not about to undermine a conservative and compliant partner. Both governments assumed Okinawans would buckle and accept another base. They were wrong.

There’s a reason why Tokyo and Washington repeat their “only solution” mantra: it serves to stifle a genuine debate over Futenma’s strategic value. If Americans and Japanese started to question why they are imposing a base on Okinawa for no appreciable gain in security, their governments might be forced to admit that the Henoko relocation is, in fact, no solution at all.

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