America’s war in Afghanistan is winding down, but the U.S. must worry about conflict elsewhere. Once viewed as inconceivable, war between China and Japan now looks possible, though thankfully still unlikely. Tokyo should get serious about its own defense.

The U.S. used its power as occupier after World War II to impose a constitution on Japan which forbade possession of a military. But America lost its enthusiasm for that arrangement early during the Cold War. When Washington subsequently pushed Tokyo to rearm, the latter hid behind its constitution.

Japan’s neighbors also opposed a Japanese military revival, preferring to rely on America for defense. Moreover, there were political points to be scored from attacking Tokyo. And Japan made itself an easy target when officials refused to apologize for their nation’s previous misbehavior.

But the world is changing. World War II is long past. Most Japanese citizens seem prepared for their nation to become like other ones. So does their new prime minister, Shinzo Abe. And that means defending themselves in a more dangerous world.

The Democratic People’s Republic of Korea is building missiles and testing nuclear weapons. The People’s Republic of China is expanding its military and growing more assertive internationally.

Moreover, America no longer can afford to protect most of the known world from any and all threats. Despite the so-called “pivot” to Asia, U.S. forces will not remain forever. In fact, Prime Minister Abe publicly worried: “With the U.S. defense budget facing big cuts, a collapse of the military balance of power in Asia could create instability.”

Tokyo’s first duty is to protect Japan. Although the PRC is unlikely to attempt to swallow Japan, there is no more vital task than protecting one’s homeland against any exigency.

Moreover, the Japanese government should promote regional security, cooperating closely with other democratic countries in East Asia. Tokyo also should work with less democratic states to maintain a balance of power in the region, and especially to help ensure that China’s rise remains peaceful.

Of particular importance for Japan is keeping sea lanes open and protecting international commerce. China’s expanding navy, which launched its first aircraft carrier last year, has raised concerns throughout East Asia. Japan no longer should rely on America to guarantee the former’s economic interests.

Moreover, Tokyo requires the means to enforce its sovereignty claims. China, Taiwan, the Philippines, Brunei, Malaysia, South Korea, and Vietnam all join Japan in claiming to own various islands, islets, and rocks, control of which yields ownership of surrounding fishing grounds and energy fields. Exactly who owns what depends on international treaty and law, control and occupation, and historical connection. Good lawyers make good arguments, but good militaries are even more important.

For years Tokyo’s defense spending only averaged one percent of the GDP—and has not increased since 2002. Still, Japan has created a capable “Self Defense Force.” And Tokyo doesn’t need a large army, which would worry its neighbors. Most helpful would be missiles and missile defenses, as well as additional air and naval assets.

These issues have taken on new urgency in light of East Asia’s burgeoning territorial disputes. Japan is squabbling with South Korea over the Takeshima/​Dokdo Islands and with Russia over the Northern Territories/​Kurile Islands. In both cases Tokyo is contesting the status quo. The disputes are bitter, but unlikely to turn violent.

More dangerous is Beijing’s challenge to Japanese control over the Senkaku (called Diaoyu in China) Islands. These five islets have sparked naval clashes, aerial chases, activist flotillas, and domestic protests. Prime Minister Abe declared that the Senkakus are “Japan’s inherent territory” so “There is no room for diplomatic negotiations over this issue.” Indeed, he added, the solution necessitated, “if I may say at the risk of being misunderstood—physical force.”

Although Beijing has perhaps the better claim to the islands, there’s nothing in principle wrong with Japan taking such a hard-line position—so long as Tokyo bears the cost of giving 1.3 billion Chinese the diplomatic equivalent of the finger. (In late January the prime minister sent an envoy to Beijing with a conciliatory letter to incoming Chinese President Xi Jinping.)

Alas, Japan would not have an easy time if the two navies engaged. Reported Michael Auslin of the American Enterprise Institute: “Japan may have a qualitative edge, but that would be worn down by China’s ability to flood a combat zone with ships, subs and planes. Tokyo would be forced to turn to the United States for support under the mutual security treaty.”

Which is why in November then-Defense Minister Satoshi Morimoto proposed updating the U.S.-Japan defense guidelines to include the Senkakus. He cited “the problem of China’s increasing maritime activities” and expressed his desire “to start a revision of the present state of the U.S.-Japan alliance.” Former Vice Defense Minister Akihisa Nagashima explained: “As we witness China’s spectacular rise, Japan and the U.S. must together consider hedging against the fallout.”

Discussions will begin soon. The outcome seems foregone. In 2010 Secretary of State Hillary Clinton refused to take any position on territorial sovereignty, but explained: “we have made it very clear that the islands are part of our mutual treaty obligations, and the obligation to defend Japan.” More recently unnamed State Department officials stated that the defense treaty applied.

Unfortunately, issuing blank checks for the defense of weaker allies rarely turns out well. Doing so encourages the latter to behave irresponsibly, as, in fact, has Tokyo. The Japanese government refuses to negotiate after politicizing the issue by purchasing three of the rocks. Moreover, Japan has done little to prepare for a military confrontation, instead relying on Washington to take up the slack.

Of course, Tokyo isn’t alone. Even worse is the Philippines, whose naval flagship is an American cast-off. Yet Manila wants Washington’s backing for its claim to Scarborough Reef, called Huangyan Island by China. Years ago the Filipino defense minister lamented that his nation had a navy which couldn’t sail and an air force which couldn’t fly. Not much has changed.

Washington should reject Tokyo’s (and Manila’s) invitations to put Americans at risk to guarantee those nations’ contested and peripheral territorial claims. More broadly, the U.S. should stop treating its allies, especially Japan, as helpless dependents. Rather than augmenting American military forces in the Pacific, Washington should begin turning defense responsibilities over to Tokyo. (The plight of the Okinawan people on an island crowded with U.S. military facilities—highlighted by an alleged sexual assault by an American in October—adds a special imperative to act there.)

The U.S. should remain an interested party in Asia, acting as an “off-shore balancer” if a truly dangerous hegemonic threat to the region arise. But when it comes to ship-bumping throughout East Asian waters, those countries with interests at stake should expend the resources and accept the risks.

This process has begun. Both Australia and South Korea have grown more skeptical of Beijing’s embrace. Several Southeast Asian states have begun building submarines to deter China, just as China has been building them to deter America. India is building relationships throughout Southeast Asia.

But the greatest responsibility falls on Tokyo. Prime Minister Abe once criticized Article 9 of the Japanese constitution for “failing to provide a necessary condition for an independent nation.” He indicated that his government will reconsider the informal one percent limit on military spending and may acquire amphibious units, ballistic missiles, and strategic bombers. Such increased military activity “may even cause Beijing to think twice about the cost of pushing its military and economic weight around East and Southeast Asia,” argued John Lee of Sydney University.

Tokyo also needs to forge better working relationships with its neighbors. Michael Green of CSIS observed that East Asian countries are “finding out that they’re all on the receiving end of a Chinese strategy which aims at pushing China’s maritime sphere outward,” which “has spurred them towards a more strategic cooperation.” Japan has been holding joint exercises, making port visits, and offering military aid.

There remain serious obstacles to cooperation among disparate nations with disparate interests. Only Tokyo, for instance, is vitally concerned about the Sea of Japan. Getting other states to look north will be difficult.

Historical antagonisms loom even larger. Yoshihide Soeya of the Institute of East Asian Studies at Keio University said that “We want to build our own coalition of the willing in Asia to prevent China from just running over us.” However, potential partners remember when Japan ran over them.

Unfortunately, Prime Minister Abe has exacerbated these concerns by contradicting past apologies for the World War II impressment of “comfort women” to provide sexual services for Japanese soldiers. Many of his cabinet members take a similar position, “gripped by a backward-looking, distorted view of history that paints Japan as a victim,” complained the Economist magazine. Moreover, the dispute over the Takeshima islands has undermined efforts to expand Japanese-South Korean security cooperation.

The prime minister has begun to address these concerns. He welcomed the election of Park Geun-hye as the ROK’s incoming president and appointed a special envoy to improve relations with Seoul. Abe explained: “Since both countries have new governments, I would like us to make a good start to our relationship.”

Prime Minister Abe’s first overseas trip was to Southeast Asia. Tokyo has signed a defense memorandum with Singapore and even the Philippines, occupied during World War II, has welcomed Tokyo’s increasing maritime role in the region. Rommel Banaoi of the Institute for Peace, Violence and Terrorism Research said: “We have already put aside our nightmares of World War II because of the threat posed by China.”

The ultimate objective is to convince the PRC that it has too many prosperous and nationalistic neighbors with expanding militaries to achieve primacy. Beijing should recognize that the more it asserts itself, the more surrounding states will respond. Hopefully China will reach the same conclusion as Kailash K. Prasad of the Delhi Policy Group: “it is difficult to decipher what advantage the [Chinese navy] hopes to wield in the long term. Hegemony in the Pacific and Indian Oceans seems unlikely. Anything less could leave Beijing more isolated and vulnerable in a powerful, distrustful backyard.”

Some analysts say a defense shift to Japan is necessary, but not yet. Bruce Ackerman of Yale and Tokujin Matsudaira of Teikyo University argued that the Obama administration “should reject all efforts by the Japanese government to take a more prominent military role in its long-standing alliance with the United States” until it sees “whether the Japanese people build upon, or repudiate, their postwar experiment in liberal democracy.” Yet Japan’s record over the last six decades has answered that question. Last month a frustrated electorate focused on economic issues and only reluctantly returned the Liberal Democratic Party to power. There is no popular support for recreating Imperial Japan. It should be obvious which poses a greater threat to regional peace, a rising China or a revived Japan.

Of course, the mere fact that peace is in every country’s interest does not guarantee peace. Assistant Secretary of State for East Asia and Pacific Affairs Kurt Campbell recently expressed the administration’s “desire to see cooler heads prevail and the maintenance of peace and stability over all.” However, a nationalistic storm is building throughout the region. Warned Thomas Berger of Boston University: “What is really driving things is raw nationalism and fragmented political system, both on the Japanese and even more so the Chinese sides, that is preventing smart people from making rational decisions. He added: “No Chinese or Japanese leader wants or can afford to be accused of selling out their country.” The same is true in varying degrees of the Philippines, Vietnam, India, and other states.

But the possibility of conflict is a powerful reason for the U.S. to stay out. America has an interest in preventing any nation from dominating Asia, but no power, including the PRC, will be able to do so in the foreseeable future. In contrast, the U.S. has no interest in acting as umpire for bitter territorial feuds throughout the region.

As America winds down more than a decade of fighting in Central Asia, some analysts would have the U.S. prepare for war in the Pacific. But Washington should reject this invitation for perpetual conflict. Japan and its neighbors should cooperate to counter Beijing’s geopolitical ambitions.