America counts heavily on a cordon of allies stretching from Japan to the north down to Thailand, and across to India, in the highly unlikely event of war with China. But these same allies could draw the U.S. into strictly local disputes in which America does not always have a clear security interest and which could destabilize the region.

Asian powers including India and Japan possess large, sophisticated navies and air arms which, combined with U.S. Pacific forces, could outgun the rapidly-modernizing People’s Liberation Army in wartime. And in peacetime, these same regional powers can help as counters to Beijing’s growing influence.

In most conflicts short of war in Indo-Pacific Asia, however, Washington must be careful not to take sides, for backing allies in even minor spats could come at the cost of regional stability, experts say.

The challenge for U.S. policymakers, therefore, is to build ties with Asian powers that balance China’s growing strength without antagonizing Beijing or sucking Washington into a war. China is not, after all, America’s enemy, the experts point out. And armed conflict between the U.S. and China is not preordained.

To assume war is inevitable risks “letting the tail of conflict wag the dog of cooperation,” warns Bernard Finel, from the National War College in Washington, D.C. In the interest of encouraging Beijing’s peaceful rise, the U.S. should “vigorously” engage China — particularly in areas where the two countries agree, Finel says. (He adds that this view is his alone and does not represent the official position of the National War College.)

That doesn’t mean the Washington shouldn’t also engage its closest and most powerful allies in China’s backyard. But it does mean America should be mindful of its friends and their agendas, and resist the temptation to automatically back allies in their bilateral disputes.

The Unsinkable Aircraft Carrier

Nearly 50 modern frigates and destroyers; two helicopter carriers; 18 large, quiet diesel-electric submarine with more under construction; sea-based ballistic-missile defenses; the largest F-15 fleet outside of the U.S. Air Force; F-35 stealth fighters in the acquisitions pipeline and a homegrown stealth fighter demonstrator in development. This is the Japanese Self-Defense Forces. The maritime branch, in particular, “is the most capable navy in East Asia,” say Bernard Cole, also from the National War College. (Cole, too, says his words reflect his personal opinion.)

Moreover, Japan’s air bases represent an “unsinkable aircraft carrier” for the U.S., as then-Prime Minister Yasuhiro Nakasone put it in 1983.

The U.S. Air Force Base at Kadena in Japan’s southern prefecture of Okinawa is particularly important. Home to a USAF F-15 wing, E-3 radar planes and aerial tankers, Kadena is within unrefueled range of China for tactical jets and boasts extra ramp space, hardened hangars and fuel and ammunition supplies for potentially hundreds of reinforcing aircraft.

Since World War II Japan has been careful not to show off its military power, and to this day constitutional restrictions limit how much Tokyo can invest in its armed forces — one percent of GDP, or roughly $60 billion — how far from home it can deploy them and just what it can build and buy. In wartime, the SDF can legally accept mission-tasking from U.S. commanders for operations up to 1,000 miles from Japanese shores, Cole explains.

In practice, however, Japanese ships and aircraft will probably rarely stray beyond national waters and airspace, says Owen Cote, an analyst at the Massachusetts Institute of Technology. “When you start see bullets flying, they [will] really focus on the home game,” he says of the Japanese.

But Japan’s claimed territorial waters border, and in some cases overlap, with some waters China claims. Japaneses forces do not have to travel far to weigh heavily on the regional balance of power.

Even so, the Japanese navy and army are quietly assembling an expeditionary force capable of projecting power into more distant, contested waters, a major shift from the past. In 2010 Tokyo announced the establishment of a naval infantry force. A year later in California, Japanese army troops trained alongside the U.S. Marine Corps in beach landings and air assault operations.

This year, against the background of a loosening interpretation of its anti-war constitution, Toyko purchased surplus U.S. Marines amphibious tractors to complement an existing force of landing craft, transport hovercraft and amphibious landing ships.

So, unnoticed by much of the world, Japan now possesses a de facto Marine Corps of its own — and a growing political rationale for using it. At the Shangri-La defense summit in Singapore in June, parliamentary senior vice-minister of defense Shu Watanabe called China’s $106-billion military budget for 2012, an 11-percent jump over 2011, a “threat.”

Japan’s rearmament has caught Beijing unaware. “My own view is that China has for at least a decade underestimated Japan’s naval capabilities,” Cole says.

The same cannot be said of Washington. Stronger military ties to Japan are on the agenda of Mark Lippert, newly confirmed assistant Secretary of Defense for Asian and Pacific security affairs. “The United States needs a more capable alliance with Japan,” Lippert wrote in response to questions from Congress.

For good reason. In key categories — modern submarines, for instance — the Chinese People’s Liberation Army’s eastern forces outnumber the forces of U.S. Pacific Command. But add in Japanese ships, planes and Marines and the balance shifts in America’s favor. And, of course, most analysts believe U.S. ships boast capabilities superior to those of the Chinese fleet.

And that’s without even factoring in India.

The Indian Ocean Spoiler

Left out of many discussions of U.S. Pacific strategy is a key, adjacent body of water. The Indian Ocean connects to the Western Pacific via the narrow Strait of Malacca between Indonesia and Malaysia. The majority of China’s (and much of Japan’s) energy imports must pass through the strait, making it a strategic chokepoint for the world’s second-largest economy.

Control the strait and you control China, to a large degree. So important is the Indian Ocean to the regional balance of power that Rory Medcalf, an analyst with Australia’s Lowy Institute, prefers to use the term “Indo-Pacific Asia” instead of the more common “Asia-Pacific.”

In that context, Beijing has big problems. India, Medcalf says, is “strategically placed astride the vital Indian Ocean sea lanes.”

On the strength of an approximately $40-billion-a-year military budget, India’s air and naval power are fast expanding. New Delhi possesses a potent air force, including some 150 Russian-made Su-30 fighters. In January the government selected Dassault’s Rafale fighter to fill a 126-plane requirement. Looking ahead, India is co-developing the Sukhoi T-50 stealth fighter alongside Russia. And India has not ruled out buying the Joint Strike Fighter.

New Delhi also operates 14 diesel submarines, with another six on order, plus a single, Russian-made, nuclear-powered Akula-class sub. Domestically-designed nuclear subs are under development.

This summer the Indian navy began sea trials of its new aircraft carrier Vikramaditya, a refurbished and modernized former Russian flattop displacing 44,000 tons. Vikramaditya is scheduled to join the existing 28,000-ton former British carrier Viraat in frontline service in December. Along with a combined force of Sea Harrier and MiG-29K naval fighters, India will soon have the biggest flattop fleet in Asia.

China, by contrast, “remains a long way from being a militarily powerful player in the Indian Ocean,” Medcalf says.

This imbalance helps explain why Beijing is willing to invest decades and potentially billions of dollars in activating a single carrier, the ex-Russian Varyag. The 65,000-ton vessel began sea trials in July 2011 but has yet to launch a fixed-wing plane. And China is believed to be as many as 10 years distant from fielding an operational carrier with a full complement of fixed wing aircraft.

Against the U.S. Pacific fleet, the ex-Varyag is “irrelevant,” Cote says. “But it is not irrelevant for traditional naval fighting between medium-size powers,” he adds. With one aged, medium-size carrier Beijing can’t hope to match America’s five Pacific-based supercarriers. But it stands a chance at balancing India’s flattops in some situations.

That would not be true during a full-scale war, during which India’s carriers would likely have serious backup. The nations of Indo-Pacific Asia are woven together in a thickening web of crisscrossing relationships meant to blunt China’s growing power and assertiveness. Cote calls India and Japan “virtual allies.”

“Japan-India relations are highly cooperative and this is partly because of China,” Medcalf adds. “This is not an alliance, and will not become one, but both nations are uncertain about what China’s growing power means for them.”

“Since China has increased their military capabilities and spending more on defense, in our own way, to protect our national interest, we are also strengthening our capabilities in our borders,” AK Antony, India’s defense minister, said at the Shangri-La summit.

As China looms, America’s stature in Indo-Pacific Asia grows in proportion. “What is important to understand about regional perceptions is that many countries seem positive about continued U.S. engagement, even anxious to retain it,” Medcalf says.

Existing military relations with Japan and India aside, in recent years the Pentagon has also made overtures to Vietnam and revived basing agreements with The Philippines.

Then there’s the tiny city-state of Singapore, which lies astride the Malacca Strait and is “procuring a formidable force” mostly of U.S. made-weapons, and is expanding its joint training with American troops, Cote says. “And it’s not because they’re worried about Malaysia.” The Littoral Combat Ship will, for example, spend a great deal of time operating from Singapore.

Island Spats

The downside for America in this arrangement is … anything short of major war. The Western Pacific roils with minor territorial disputes, particularly over small islands in the China Seas that could sit atop huge mineral reserves and are often claimed by two or more countries.

The same weaponry that makes a country such as Japan a key asset for the U.S. in wartime can represent a liability during peacetime conflicts, as it introduces the potential for violence into what should be diplomatic exchanges.

This summer Tokyo announced plans to buy from a private Japanese citizen a cluster of uninhabited islands in the East China Sea that the Japanese call the Senkakus. Beijing also claims what it dubs the Diaoyu Islands, the waters around which are believed to contain extensive natural gas deposits.

Tokyo’s plan sparked a serious international row. Chinese protesters occupied the islands and were arrested by Japanese authorities, sparking angry demonstrations in China. In July, Japan recalled its ambassador in Beijing. Japanese Prime Minister Yoshihiko Noda warned that his nation’s military could get involved and, as tensions rose, both Chinese and Japanese warships sortied for training exercises.

Japan’s mobilization should not be seen as a call to action for the U.S. Equally, Chinese moves in this context should not necessarily be mistaken as affronts to U.S. national security or America’s status in Indo-Pacific Asia. In firmly, but so far peacefully, confronting Tokyo over the islands, Beijing is not threatening the U.S. — and Washington’s policy should acknowledge that, the experts contend.

Instead, the U.S. should aim to selectively engage, deter and stabilize as China, Japan, India and other regional nations compete with each other for influence, land and resources. “Any American strategy has to be highly attuned to the shifts within China on any of these issues, rather than a blanket policy of either engagement or deterrence,” Medcalf advises. “There is no one-size-fits-all approach.”

That means more diplomatic and military exchanges and more cooperation with China. And it means taking care not to blindly bolster existing allies with arms sales, exclusive military alliances and diplomatic backing in regional conflicts.

That “offshore balancing” approach to international relations “almost encourages or cultivates regional disputes,” Finel warns. “It’s not healthy.” Certainly, throwing America’s weight behind an ally’s beef with China over some minor Pacific island is not a wise application of U.S. power.

“We may get to the point where we have to balance them or contain them, but it’s really premature,” Finel says of the U.S. approach to China. “I prefer a much more vigorous engagement policy where we focus mostly on areas of agreement … as opposed to focusing on the relatively small areas of disagreement.”

Finel cites counter-piracy and freedom of navigation as areas where the U.S. and China could cooperate more closely, even as China wrestles with its neighbors. Cooperation could even have the effect of easing regional tensions if it helps Beijing align with international norms.

Defense Department assistant secretary Lippert agrees. “I would look for ways to deepen and enhance our military-to-military relationship with China, and to encourage China to act responsibly both regionally and globally,” he said.

America’s heavily-armed friends in Indo-Pacific Asia mean the U.S. doesn’t have to worry too much about losing in a thankfully unlikely shooting war with a rapidly-arming China. The naval and air arms of Japan and India, in particular, make up for any local numerical advantage in ships and plane that China might hold over U.S. Pacific forces. It also means the U.S. and its allies possess a wide variety of powers and tools with which to help manage their relations with China.

But the same friends, empowered and wary of Beijing, are increasingly involved in conflicts with China in which the U.S. sometimes has no national interest. America should not mistake regional disputes for a war it must fight.