The Japanese government's decision to increase its defense spending to 2% of gross domestic product has grabbed headlines around the world.

Given the financial challenges that the nation is facing, Tokyo will obviously want to carefully consider the most efficient way to provide a complete 360-degree defense strategy before committing trillions of yen that the country cannot easily fund.

A significant amount of the budget increase will be used to purchase new weapons, including those that will give the Self-Defense Forces counterstrike capabilities. Japan’s prioritization of these assets is understandably targeted at the countries that pose the most immediate and severe security threats: China and North Korea. But those threats largely come from the north and west of the country.

Although perhaps less critical, Japan also needs to be concerned with threats that could form in the Pacific region to its south and east. The region is home to more than a dozen small island states that are spread throughout the Pacific Ocean.

In addition to providing important support for Tokyo in international forums, it is from the "Pacific Island Countries" and their extensive maritime territories that Japan imports significant quantities of food, resources and fuel, as well as through which additional imports and exports travel. From a strategic perspective, the Pacific region is also where a hostile force could — but thus far has not been able to — base military assets.

Because of the importance of this region, threats to the Pacific Island Countries are also threats to Japan. The list of threats includes climate change, illegal, unreported and unregulated fishing, high levels of noncommunicable diseases and underdeveloped medical systems. The paucity of educational and economic opportunities, a lack of physical infrastructure and limited governance capabilities that are the result of small populations are also of concern.

Tokyo’s new strategic posture recognizes these challenges are of a different nature from those emanating from countries to the north and west, so what does the government plan to do about them?

To answer this question, Tokyo must understand and be responsive to the security challenges facing the Pacific region. Only by winning the support of the island states can Japan ensure a favorable security environment for one half of its desired 360-degree defense strategy.

The time to address this issue is now, before Tokyo allocates new defense-related funds and before it issues a new "Free and Open Indo-Pacific Strategy" document in the spring. Doing so, though, requires having people on the ground throughout the region who can report back first-hand information on, and an understanding of, the specific challenges faced in each Pacific Island Country.

Although Japan is actively engaged in the Pacific region, including through its hosting of the triennial Pacific Islands Leaders Meeting (PALM) and funding of the Pacific Islands Center in Tokyo, it does not have a mission or special envoy to the Pacific Islands Forum (PIF), the leading regional political organization. Japan also does not have a permanent diplomatic representative in Nauru, Tuvalu, the Cook Islands or Niue. The Japan International Cooperation Agency, which is the nation’s main conduit for the provision of overseas development assistance, similarly does not have a permanent office in these countries.

Collaborating with its like-minded partners can help efficiently fill these gaps in coverage.

For example, rather than opening a new embassy, Japan could co-locate a diplomatic presence, sharing a building and other on-the-ground resources with a close partner such as Australia (which now has an embassy in every member state of the PIF) or the United States (which recently appointed a special envoy to the PIF). This idea is not new: The United Kingdom and New Zealand co-locate their High Commissions in Tonga and Vanuatu, while Germany, the Netherlands and the U.K. share a location in Tanzania.

The more glaring hole in Japan’s presence, though, is the dearth of in-person meetings between the nation's two-most senior foreign policy officials — the prime minister and foreign minister — and regional leaders.

A review of the press releases posted on the prime minister’s official website shows that between the last PALM in July 2021 and the start of this February, Japan's leader had only one meeting with the head of a Pacific Island Country and has not traveled to the region at all.

A similar review of the Foreign Ministry's website shows that prior to Foreign Minister Yoshimasa Hayashi’s meeting with the president of the Federated States of Micronesia on Feb. 2, and meetings with the foreign minister of the Republic of the Marshall Islands and prime minister of the Cook Islands the following week, the last bilateral meeting between Japan's top diplomat and a Pacific Island Country leader was at the start of last September — nearly half a year ago — and that was just a 15-minute phone call.

This lack of engagement by senior officials stands in stark contrast to Australia and, increasingly, the United States.

Australian Foreign Minister Penny Wong visited each Pacific Island Country within seven months of taking office this past May. Anthony Albanese, the prime minister of Australia, for his part visited Papua New Guinea in January, hosted the Solomon Islands’ prime minister in October and personally attended the PIF Leaders’ Meeting last summer (Australia is a full member of the PIF).

The United States, while not yet as active as Australia, has still shown more engagement with the region than Japan has over the past year: Vice President Harris addressed the PIF Leaders’ Meeting last summer, followed by President Joe Biden hosting island country leaders at the White House in the fall. Other senior U.S. administration officials have also traveled to and met with top officials from the region during the last year.

The Pacific Island Countries may be small and able to only offer a fraction of what other regions can in terms of economic opportunity for Japanese business, but they are still the country's neighbors, have a long-shared history and legally control vast swaths of open ocean that comprise Japan’s southern and eastern boundaries.

Pacific Islanders care about being heard and notice when a country’s actions do not match its words. Because winning the hearts and minds of Pacific Islanders is critical to a 360-degree defense strategy, these gaps in engagement may prove costly, raising openings for others to exploit and doubts about Japan’s commitment.

As it happens, there is currently an ideal opportunity for Tokyo to show it is respecting Pacific Islanders and listening to their concerns.

Countries from the region have made it clear that Japan has not yet convinced them that it is safe to release contaminated water from the Fukushima nuclear plant. Indeed, it was for this reason that a high-level PIF delegation traveled to Tokyo earlier this month for in-person talks with the prime minister.

The result of this meeting is unclear: While the PIF readout of the meeting implies there was an agreement to delay the water’s release, Japan’s statement does not. For the residents of the islands, the Pacific Ocean is an important part of their personal identities; polluting it would be akin to using Mt. Fuji as a landfill for the Japanese. Moving ahead with the Kishida administration’s plan before winning Pacific Islanders’ support risks setting back decades of Japan's efforts in the region, directly undermining its attempts at establishing a favorable security environment.

Japan’s new National Security Strategy correctly recognizes that not all of the nation’s security challenges can be solved with more missiles or weapons. Tokyo should therefore prioritize engagement — at the most senior levels — with the Pacific Island Countries, work with its partners to establish a presence in each country and send senior officials for regular, in-person visits.

By taking the time to listen now, Japan may be able to achieve its security goals without needing to spend quite so much money that it cannot easily afford.

Daniel Mandell is a Council on Foreign Relations/Hitachi Ltd. international affairs fellow and a visiting research fellow at the Japan Institute of International Affairs.