Japan could win a war for the Senkaku islands,
but it wouldn't be easy. And certainly not
without U.S. help. BY JAMES HOLMES | SEPTEMBER 28, 2012 In recent weeks, Japan and China have squared
off over who owns a minor group of islands in
the East China Sea. The unthinkable -- a perilous
maritime war for seemingly trivial stakes -- no
longer appears unthinkable. So how do you
defend a group of uninhabited rocks and islets like the Senkaku/Diaoyu islands?
Mainly by positioning yourself to win the air and
sea battle around the disputed archipelago. The
obvious way to ward off attack -- stationing
garrisons and artillery on the tiny, resource-poor
islands -- should be a secondary measure. And it
would likely prove a losing one, absent superiority in nearby seas and skies. Forces left
ashore without external support would find
themselves stranded and outgunned, not to
mention hungry and thirsty. To be sure, heavily armed ground detachments
can convert islands with rugged terrain into
virtual "porcupines," prickly to the touch. For
instance, Japan Ground Self-Defense Force (GSDF)
troops equipped with truck-launched anti-ship
cruise missiles could give any naval assault force fits. They could dig in, hardening their positions
against air and missile bombardment. Despite
their small numbers, GSDF defenders would be
exceedingly tough to dislodge. But only for a time. Whoever controls the sea and
sky will ultimately determine the islands' fate. If
U.S.-Japanese naval, air, and ground forces can
hold open access to the islands while fending off
Chinese assailants, the allies would stand to win a
limited clash. They can resupply defenders perched there, letting them hold out more or less
indefinitely. But if China's People's Liberation
Army (PLA) wrests control of the air and sea
commons from the allies, on the other hand, it
will be at liberty to cordon off the islands and
starve out the defenders. And then Beijing will stand to win. Were a battle over the Senkakus/Diaoyus to take
place today, I would give China the edge, even
though Japan holds the contested real estate and
the United States has committed itself to the
islands' defense. Geography and force are the
main reasons why. First consider the islands' geographic merits and
drawbacks. The great fin de siècle seapower
theorist Alfred Thayer Mahan classifies
geostrategic assets by their position, strength,
and resources. The Senkakus/Diaoyus occupy an
awkward position near the southern tip of the undefended Ryukyus chain, closer to Taiwan
than to the Japanese main islands and roughly
equidistant between Okinawa and the Chinese
mainland. The archipelago's natural defenses are
so-so at best, owing to its small size and
fragmentation into several islets. The island chain's geography opens up options
for a determined attacker. Rather than mount a
full-scale assault, PLA occupiers could grab one
island, place weaponry on it, and pummel
Japanese GSDF sites from there -- seizing the rest
over time through salami-slicing tactics. And since the islets offer virtually no natural resources
to support garrisons, everything would have to
be shipped in by sea or air. If China rules even a
pocket of sea and airspace around the islands, it
will probably get its way in a test of arms.
In Mahan's terms, the Senkakus/Diaoyus are like
Gibraltar -- without the ideal strategic position or
the forbidding natural defenses. And like
Gibraltar, they would be entirely dependent on
outside logistical support in wartime. Their
geostrategic potential is minimal by all three of Mahan's measures. Which leads to the configuration of forces.
Mahan's British contemporary and sometime
rival, British theorist Sir Julian Corbett, observes
that limited maritime war is the prerogative of
the belligerent that can isolate the theater
through naval action while shielding its homeland from an "unlimited," asymmetric
counterstroke -- a strike that would disarm its
military from afar, unseat the government, or
otherwise compel it to sue for peace. The antagonist whose armed forces can make
the sea an "insuperable physical obstacle" to
enemy action enjoys the luxury of concentrating
overpowering military might at decisive points in
the theater -- improving its expeditionary forces'
prospects of attaining operational, strategic, and political goals. The U.S.-Japan alliance is unlikely to
escalate to strikes against the Chinese mainland
for the sake of the Senkakus/Diaoyus. Japan has
little capacity to mount such a threat, whereas
the logic of nuclear deterrence eliminates any real
chance of the United States' doing so. And thus, if the PLA can seal off the archipelago, it will meet
Corbett's standard for limited war. The allies will
never fully meet that standard. If Tokyo wants to hold the islands over the long
term, then, it needs to do some basic things. First
and foremost, Japanese commanders and officials
must figure out how to pry open and keep open
access to the islands should the PLA actively
dispute their access -- as it will, should China and Japan come to blows. Local command of the
commons may demand staging naval and air
forces in and around the Ryukyus, closer to the
likely scene of combat. Second, Japanese commanders must consider
how to bar Chinese access to the embattled area.
For example, deploying mobile anti-ship missiles
on Yonaguni Island, at the extreme southwestern
tip of the Ryukyus, would allow the GSDF to hold
Chinese surface ships at risk around the Senkakus/Diaoyus. Stationing weaponry on the
islets themselves would generate overlapping
fields of fire. Mining nearby waters is worth
considering, as is building large numbers of small,
stealthy combatant ships armed with anti-ship
missiles. Swarms of unobtrusive but deadly small craft could ruin Chinese commanders' whole day.
Indeed, Beijing has premised its "anti-access"
strategy vis-a-vis the U.S. Navy in part on such
craft. Tokyo can take a page from Beijing's book,
fashioning a small-scale, anti-access zone of its
own. Finally, Japanese officials must not overlook the
politics of island defense. Blunting a PLA offensive
may not come cheap, either in the Senkakus/
Diaoyus or elsewhere. It is high time for Japan to
reconsider its unofficial cap on defense spending,
which has stood at 1 percent of gross domestic product for decades. This is not a serious enough
commitment for a nation facing Japan's
geostrategic predicament. And however sincere Washington's assurances
about helping defend the archipelago, Tokyo
should not bank on its doing so with any real
enthusiasm. U.S. leaders will not attach the same
value to the Senkakus that Japan does. That
disparity is apt to beget differences within the alliance over strategy and operations. To keep
open their options, Japanese leaders should think
ahead toward fielding weaponry and developing
strategy for going it alone. Defending these uninhabited islets, then,
represents a microcosm of the larger dilemmas
confronting Japan in maritime strategy. It poses a
test of a high order for the Japanese military
services -- and for the nation as a whole.