Japan's Defense White Paper Sounds Alarm Over China's ‘Gray Zone' Activities

The Diplomat

15-07-2025

For the first time, the annual white paper expressed Japan's concern over the expanding military role of the China Coast Guard.
This handout photo, provided by the Japan Coast Guard, shows a China Coast Guard vessel and a helicopter within the territorial waters of the Senkaku/Diaoyu Islands on May 3 2025.
In its latest defense white paper, Tokyo for the first time sounded the alarm over China's 'gray zone' activities – particularly the expanding role of the China Coast Guard, which is strengthening its cooperation with the Chinese military.
'The Chinese military and the China Coast Guard have been conducting joint navigation and joint training. This strengthening of cooperation between the military and the People's Armed Police, including the China Coast Guard, is thought to be intended to improve operational capabilities in gray zone situations,' the annual defense white paper, titled 'Defense of Japan 2025,' pointed out.
The 'gray zone' refers to a wide range of ambiguous situations that blur the boundaries of peacetime and wartime.
'In a gray-zone situation, for example, a country that confronts another over territory, sovereignty or maritime and other economic interests uses some forceful organization to demonstrate its presence in the relevant disputed region in a bid to alter the status quo or force other countries to accept its assertions or demands,' the Japanese defense paper, published on July 15, explained.
Gray zone situations also include hybrid warfare, such as cyber attacks and cognitive warfare, which intentionally blur the line between military and non-military activities. 'The so-called gray-zone situations harbor the risk of rapidly developing into graver situations without showing clear indications,' the white paper said.
The report noted that the People's Armed Police Force (PAP), a paramilitary force generally tasked with both internal security and support for the People's Liberation Army (PLA), has the China Coast Guard under its umbrella. The CCG is said to be the world's largest maritime law enforcement agency.
'In recent years, the China Coast Guard's vessels have become larger and more armed. At the end of December 2024, the China Coast Guard possessed 161 ships with full load displacement of 1,000 tons or more, including two 10,000-ton-class patrol ships, among the world's largest ones,' the paper stated.
The annual report noted the increasing number of military exercises by the Chinese military around Taiwan as part of its concern over gray zone activities:
There is growing concern over China's pursuit of unification through gray-zone military activities. Some point out that military intimidation, blockades, and other such means are currently China's main options to be used against Taiwan. In the event of a blockade of Taiwan, there is a possibility that China will deploy its coast guard at the forefront to carry out the blockade within the gray zone.
The defense white paper pointed out, 'In the Chinese military's exercises around Taiwan, it is believed that some military operations aimed at the unification of Taiwan, including an invasion operation against Taiwan, may be being rehearsed.' It's the first time Japan's public defense report has raised such a concern.
It described a case in which China started military exercises on May 23, 2024, just three days after Taiwan's President Lai Ching-te gave his inauguration speech. At that time, China publicly announced for the first time that the China Coast Guard had been active in the waters east of Taiwan.
Furthermore, the paper noted that 'during the exercise in October 2024, Chinese Coast Guard vessels sailed around Taiwan, and the activities of the Coast Guard have been expanding, suggesting that China may be placing greater importance on the role of the Coast Guard in creating so-called gray zone situations.'
Regarding Chinese military movements in the sea and airspace around Japan, like last year's edition, this year's defense white paper pointed out:
The Chinese Navy and Air Force have in recent years expanded and intensified their activities in the surrounding sea areas and airspace of Japan, including the area surrounding the Senkaku Islands. These activities include those allegedly based on China's unilateral claim on the Senkaku Islands, and cases involving the one-sided escalation of activities, creating a situation of great concern to Japan.
The Senkaku Islands, which are administered by Japan, are also claimed by China as the Diaoyu Islands.
The paper cited the first-ever intrusion into Japan's airspace by a Chinese military aircraft off the coast of Nagasaki Prefecture in August 2024, and the first voyage of the Chinese aircraft carrier Liaoning between Yonaguni Island and Iriomote Island in Okinawa Prefecture in September of the same year.
'China's active military activities have reached a situation that could have a serious impact on the security of our country, and this is of strong concern,' the white paper said, the first time it has used such language.
On North Korea, the defense report said Pyongyang is clearly continuing to pursue the development and improvement of its offensive capabilities, including hypersonic weapons, in an attempt to penetrate missile defense networks. Based on conical and flat warheads that have been confirmed, the white paper continued, there is a possibility that North Korea is planning to develop hypersonic weapons with different ranges and flight patterns by developing different warheads in parallel, in order to complicate the enemy's response. The report urged Tokyo to keep a close eye on North Korea's technological advances.
The white paper also noted that Pyongyang appears to continue developing nuclear weapons using highly enriched uranium in addition to plutonium.
The white paper addressed the recent close relationship between Moscow and Pyongyang. It noted that North Korea has been providing weapons and ammunition, including ballistic missiles, to Russia since 2023, and that in October 2024, North Korean soldiers were confirmed to have been deployed to Russia, and that these soldiers have now participated in combat against Ukraine. The 2024 version of Japan's defense white paper did not mention North Korean soldiers participating in the war in Ukraine.
The Chinese government quickly responded to Japan's latest defense white paper. At a press conference on July 15, Lin Jian, a spokesperson for the Chinese Foreign Ministry, expressed 'strong dissatisfaction and firm opposition' to the paper, claiming that it had incited the threat of China based on 'erroneous perceptions.' He said that the Chinese government had lodged a protest with the Japanese side.