Why did Japan’s defense minister say cooperation with South Korea and the United States is critical?

Shinjiro Koizumi said Japan faces the most severe and complicated security environment in the post-war era. He argued that cooperation among Japan, the United States and South Korea is critical to peace and stability in the region.

What did Donald Trump do that raised concerns in the Pacific region?

Trump downsized joint drills with Seoul and also praised his relationship with North Korean leader Kim Jong-un. He was quoted as lashing out at South Korea for not helping Washington fight Iran.

What did Australia’s defense minister say about North Korea during the Japan-Australia meeting?

Richard Marles said Australia was very concerned about North Korea’s nuclear programme and missile programme. He added that North Korea is the author of quite a few of the challenges the region faces.

Japan defense minister says US, S. Korea cooperation 'critical' for security

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Summary

Japan’s defense minister said in Sydney on Tuesday that cooperation among Japan, South Korea and the United States is critical to regional security. Shinjiro Koizumi voiced support for joint security cooperation while visiting Australia. His remarks came after Donald Trump downscaled joint drills with Seoul and praised his ties with Kim Jong-un. Australian Defense Minister Richard Marles said Canberra was very concerned about North Korea’s nuclear and missile programs.

Key Facts

Koizumi made the remarks while visiting Australia and speaking to journalists in Sydney.
He said Japan faces the most severe and complicated security environment in the post-war era.
Trump had downsized joint drills with Seoul before Koizumi’s comments.
Richard Marles said Australia was very concerned about North Korea’s nuclear programme and missile programme.

By AFP

Published Aug 18, 2026 1:27 pm KST

Japanese Defense Minister Shinjiro Koizumi attends the National Memorial Ceremony for the War Dead in Tokyo, Japan, Aug. 15, marking the 81st anniversary of the end of World War II. EPA-Yonhap

SYDNEY — Japan's defense minister said on Tuesday that cooperation with South Korea and the United States was "critical" to regional security, after U.S. President Donald Trump seeded doubts in the Pacific region by downsizing joint drills with Seoul.

Speaking on a visit to Australia, Shinjiro Koizumi came out strongly in support of joint security cooperation with its key defense backer Washington, and neighbour Seoul.

"As Japan faces the most severe and complicated security environment in the post-war era, the cooperation among Japan, the United States and South Korea is critical to the peace and stability of the region," Koizumi told journalists.

The Japan-Australia meeting in Canberra came hours after Trump praised his relationship with North Korean leader Kim Jong-un and lashed out at the South for not helping Washington fight Iran.

Asked about Trump's comments, Australian Defense Minister Richard Marles said his country was "very concerned about North Korea's nuclear programme as well as its missile programme, and we have consistently made that point."

"I think in the challenging world that we face... and there are many challenges, but North Korea is the author of quite a few of those challenges," he added.

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