Prime Minister Shinzo Abe’s trip to Washington demonstrated that Japan remains America’s number one Asian ally. Unfortunately, the relationship increases the likelihood of a confrontation between the United States and China.

Japan’s international role has been sharply limited since World War II. During Prime Minister Abe’s visit, the two governments released new “Guidelines for Japan‑U.S. Defense Cooperation.” The document clearly sets America against China.

First, the rewrite targets China. Japan’s greatest security concern is the ongoing Senkaku/​Diaoyu dispute and Tokyo had pushed hard for an explicit U.S. guarantee for the unpopulated rocks. Second, Japan’s promise to do more means little; the document stated that it created no “legal rights or obligations.” Tokyo will remain reluctant to act outside of core Japanese interests.

Third, though the new rules remove geographical limits from Japanese operations, most of Japan’s new international responsibilities appeared to be what Prime Minister Abe called “human security.” In his speech to Congress, the prime minister mostly cited humanitarian and peacekeeping operations as examples of his nation’s new duties.

Moreover, the guidelines indicate that the SDF’s military involvement will be “from the rear and not on offensive operations,” noted analysts at the Center for Strategic and International Studies. Defense Minister Gen Nakatani cited “ship inspection” as an example of helping America’s defense.

Fourth, to the extent force is involved, Japan mostly promises to help the United States defend Japan. For instance, Tokyo cited the fact that Japanese vessels now could assist U.S. ships if the latter were attacked while on a joint patrol.

This should be inherent to any alliance, but Narushige Michishita, at Tokyo’s National Graduate Institute for Policy Studies, noted that “technically” it remains impossible for Japanese forces to defend even a U.S. vessel in a Japanese flotilla “when an attack on that ship does not directly or will not directly threaten Japan’s security.” That means a situation which “threatens Japan’s survival and poses a clear danger to overturn fundamentally its people’s right to life, liberty, and pursuit of happiness, to ensure Japan’s survival, and to protect its people.”

In contrast, the revised guidelines begin with an affirmation that “The United States will continue to extend deterrence to Japan through the full range of capabilities, including U.S. nuclear forces. The United States also will continue to forward deploy combat‐​ready forces in the Asia‐​Pacific region and maintain the ability to reinforce those forces rapidly.” This means more and newer weapons.

Fifth, as I wrote in China‑U.S. Focus, “America’s burden will grow. Tokyo’s military expenditures have been flat for years, but now Japan plans on devoting more resources to non‐​combat activities. That will leave less for defense against what the Japanese government sees as the greatest threat, the PRC—which continues to hike military outlays. Washington will be expected to fill the ever widening gap.”

Sixth, the new rules build on the Obama administration’s explicit promise to defend Tokyo’s contested territorial claims, most importantly the Senkakus/​Diaoyus. U.S. forces will be drawn into the islands’ defense.

According to the document, “If the need arises, the Self‐​Defense Forces will conduct operations to retake an island.” The SDF would, of course, expect American support. Protecting Tokyo’s claims also encourages the Japanese government to be needlessly provocative.

Japanese and U.S. authorities also are discussing mounting joint air patrols to the edge of the East China Sea and into the South China Sea. In the latter, Tokyo is working with other countries, including Indonesia, the Philippines, and Vietnam. Thus, a U.S. plane could find itself challenging Chinese aircraft in support of a third nation’s disputed territorial claim.

President Obama argued that “we don’t think that a strong U.S.-Japan alliance should be seen as a provocation,” but it will be if directed against the PRC. Unfortunately, the new guidelines make it more likely that Washington will find itself confronting China over issues of limited interest to America.