On February 14, 2026, Japanese Foreign Minister Motegi Toshimitsu met NATO Secretary General Mark Rutte on the sidelines of the Munich Security Conference. The two reaffirmed the strategic importance of cooperation between NATO and its Indo-Pacific partners, namely Japan, South Korea, Australia, and New Zealand, collectively known as the IP4.

With concerns about China and Russia intensifying, and unease growing over the future trajectory of U.S. alliances, the IP4 has taken on renewed significance.

The grouping, originally referred to as the AP4, first drew attention when the leaders of Japan, Australia, South Korea, and New Zealand attended a NATO summit in June 2022. Since 2025, NATO has more consistently described them as its “Indo-Pacific partners,” and the IP4 label has taken hold. Cooperation has centered on four main areas: support for Ukraine, cyber defense, countering disinformation, and emerging technologies. Concrete projects in these fields are now underway.

These efforts are clearly shaped by shared concerns over Russia and China. In recent years, strategic dialogue has increased between European states that feel directly threatened by Russia – particularly the Baltic countries and Poland – and Indo-Pacific countries facing pressure from China and North Korea. The sense that the Euro-Atlantic and Indo-Pacific security theaters are increasingly interconnected has become a common refrain.

Yet the rise of the IP4 cannot be explained solely by geopolitical convergence. It also reflects unease about the United States.

For traditional U.S. allies in both Europe and the Indo-Pacific, questions about Washington’s long-term reliability have prompted efforts to deepen ties with one another. In that sense, the IP4 is not simply an adjunct to U.S. strategy; it is also part of a broader search for resilience among U.S. partners themselves.

At the same time, the United States remains central. As NATO’s leading member, Washington would normally serve as the bridge between the alliance and its Indo-Pacific allies. Indeed, in July 2024, the leaders of the IP4 held informal talks with U.S. President Joe Biden, reaffirming solidarity among countries committed to a “free and open Indo-Pacific.”

Under the Trump administration, however, cooperation between the United States and the IP4 has appeared less coordinated. Paradoxically, this has heightened European interest in strengthening direct ties with Indo-Pacific partners through NATO frameworks. In some respects, diminished U.S. engagement has encouraged greater autonomy in transregional cooperation.

Japan’s own approach has been less consistent.

In June 2025, Prime Minister Shigeru Ishiba did not attend the NATO summit, raising questions about Tokyo’s commitment. Foreign Minister Takeshi Iwaya nevertheless maintained engagement, meeting with the NATO secretary general and participating in IP4 discussions. Even so, Japan’s overall stance toward NATO and the IP4 has appeared somewhat unsettled. This ambivalence may reflect broader considerations, including the state of U.S.-NATO relations and Japan’s policy toward China.

The structural constraints facing the Indo-Pacific also differ markedly from those in Europe.

An additional factor: Western Europe includes multiple nuclear powers and is anchored by NATO’s collective defense framework. By contrast, the Indo-Pacific relies heavily on the U.S. nuclear umbrella and operates primarily through a hub-and-spokes alliance system. While minilateral initiatives such as the Quad and U.S.-Japan-South Korea trilateral cooperation have strengthened coordination, there is no NATO-equivalent multilateral security architecture in the region.

In recent years, U.S. allies in the Indo-Pacific have been encouraged – in part by Washington itself – to deepen ties among themselves. Japan-Australia defense cooperation is one example; improved Japan-South Korea relations is another. The IP4 can be seen as an extension of this trend.

Still, its limitations are clear. Unlike France and the United Kingdon, none of the Indo-Pacific’s traditional U.S. allies is a nuclear power. A framework that excludes the United States may have symbolic value, but its operational effectiveness remains constrained.

Ultimately, the IP4 is a mechanism for cooperation with NATO. It is not, at present, a self-standing security framework in the Indo-Pacific. Whether it evolves into something more will depend on both political will and strategic necessity.

If the IP4 were to take on a more defined role within the Indo-Pacific itself, beyond its cooperation with NATO, that would mark a significant development. To fulfill that potential, however, the grouping will have to navigate past its limitations.