China’s Taiwan Air Incursions: Reading the Tea Leaves

A Chinese H-6 bomber. Courtesy of Japan Ministry of Defense / Wikimedia Commons / CC BY 4.0

China’s incursions are steadily eroding Taiwan’s position in the air and sea around the island.

Though in some ways less provocative than they are portrayed, China’s recent incursions into Taiwan’s air defence identification zone (ADIZ) and the intent behind them do warrant attention. The steady drumbeat of Chinese air activity – even if it does not point to imminent conflict – does underscore the ways in which the People’s Liberation Army (PLA) can erode Taiwan’s readiness and capabilities without risking open conflict.


The incursions were the largest to date and included the single largest Chinese sortie involving the nuclear capable H-6 bomber. They occurred after the G7 countries had voiced concern regarding stability in the Taiwan straits and marked the 72nd anniversary of the establishment of the People’s Republic of China on 1 October.

It is important to contextualise these developments. The assertion that Chinese aircraft are violating Taiwanese airspace is incorrect – a country’s ADIZ is not part of its airspace. Nor is it necessarily the case that the recent large-scale sorties point to a systematic uptick in the scale of PLA Air Force (PLAAF) activity. The sorties catalogued by the Taiwanese Ministry of National Defense (MND) point to a pattern of smaller scale sorties punctuated by periodic increases in the scope and scale of air activity before normal behaviour resumes.

Typically, an uptick in the scale of Chinese sorties coincides with actions that China views as provocative, including but not limited to visits by foreign dignitaries to Taiwan, arms sales to the island and US exercises in the area. The October sorties coincided with multinational naval exercises carried out by the US, the UK and Japan in the Philippine Sea, as well as the announcement of AUKUS. They also followed on the heels of a statement by a Japanese official to the effect that Japan and Taiwan faced a mutual threat in China. Each event has prompted a verbal response from Beijing, and it stands to reason that a show of force would serve to underscore Beijing’s determination to be respected and heard on the international stage.

Alternatively, the sorties may have served as a precursor to President Xi Jinping’s 9 October speech in which he claimed that reunification would be pursued peacefully. In this context the sorties emphasise Xi’s position that any Taiwanese move towards de jure independence would constitute a basis for the use of force.

Taiwan is forced to scramble interceptors to meet each sortie, incurring disproportionate costs from fuel use and general wear and tear in the process

Finally, the sorties may reflect the PLAAF’s lobbying for a greater role in securing China’s maritime periphery. There was no National Day parade this year, and the editor in chief of The Global Times indicated that the PLAAF flights into the ADIZ took its place instead.

Military Factors

Of particular military interest are the incursions by smaller groups of predominantly surveillance aircraft such as the reconnaissance, antisubmarine warfare and electronic warfare variants of the Y-8 maritime patrol aircraft. The use of combat aircraft such as the J-16 and JH-7 Fighter Bomber, as well as the H-6, is more unusual. Moreover, data compiled by the MND suggests that sortie sizes have been typically limited, often involving one to two aircraft, and are restricted to the southern portions of Taiwan’s ADIZ, with only a limited number of sorties occurring in the Taiwan Strait.

The sorties into Taiwan’s ADIZ can serve several purposes. First, Taiwan is forced to scramble interceptors to meet each sortie, incurring disproportionate costs from fuel use and general wear and tear in the process. In 2020, Taiwan spent $1.03 billion on the costs related to intercept missions – 9% of its defence budget.

Patrolling activity by antisubmarine warfare-optimised Y-8 aircraft over the Bashi Channel – one of the few channels in the area deep enough to allow a submarine to transit submerged – could also represent an attempt to build situational awareness in an area that would be critical to both excluding foreign submarines from the first island chain and to allowing Chinese submarines to break out of it.

Additionally, from positions at the edge of Taiwanese airspace, Chinese aircraft can conduct intelligence, surveillance and reconnaissance (ISR) activities associated with mapping the locations of Taiwanese command posts, air defence systems and other critical defensive infrastructure. The radar network and command and control system that underpin the island’s air defence will represent a particularly critical target for the PLA to map in advance. Stimulating Taiwanese defenders to turn on their radar and communicate across the air defence network can allow Chinese ISR assets to collect signals and communications intelligence and track radar systems. This peacetime intelligence gathering would be crucial to the successful execution of a precision strike ‘Joint Firepower Campaign’ in the early stages of a conflict in the way that Chinese doctrine prescribes.

The incursions could present a means through which the PLA can disrupt Taiwan’s defensive rhythm

It is possible that the PLA is looking to make the opponent ‘less fast, less tall and less strong’, a concept outlined in an article published by the PLA’s Army Research Institute on 5 October 2021. At the tactical level the authors state it is possible to disrupt an opponent’s rhythm and ‘destroy the inherent procedures in its initial combat plan’. While these publications are not necessarily representative of the PLA’s ambitions, they may be indicative of the type of warfare that is considered important. In this context, the ADIZ incursions could present a means through which the PLA can disrupt Taiwan’s defensive rhythm.

The Potential Evolution of Chinese Incursions

It is possible that contemporary technology could reinforce China’s strategy of erosion. Long endurance UAVs such as the Wing Loong II and the WZ-7 could loiter in Taiwan’s ADIZ in larger numbers and for longer periods of time than manned aircraft can, potentially forcing even greater use of resources and effort to track and intercept them. It would also present challenges should they make probing incursions at or beyond the edges of Taiwanese airspace. The presence of these assets could, moreover, provide more persistent overwatch, forcing Taiwan’s defenders to take costly and time-consuming countermeasures to limit communications and conceal the locations of key assets. China already uses UAVs in a similar way near Japanese airspace. Furthermore, a PLA Daily article from April 2021 details the possible uses for ship-launched UAVs, and observed that using unmanned systems to provide persistent surveillance and antisubmarine warfare missions has obvious advantages over manned alternatives.

Given the absence of any risk of pilot loss, UAVs may also be used more aggressively than manned aircraft and could be operated directly within Taiwanese airspace. Equally, however, defenders may feel more willing to engage unmanned assets kinetically without risking war – much as Iran did with a US RQ-4 Global Hawk in 2019. Unmanned assets, in the context of China’s approach, could thus increase the risks of mutual miscalculation.

Should China seek to enforce its new coastguard law in the waters around Taiwan, steady-state aerial surveillance at sea could serve to facilitate some form of limited quarantine. This might not need to take the form of a full-scale blockade but might, for example, involve the control of the flow of arms or strategic materials into Taiwan. The spectre of a ‘Cuban missile crisis in reverse’ is one that some analysts consider to be more likely and, in certain ways, more difficult for the US to respond to than a full scale invasion. Maritime domain awareness is likely to be a prerequisite for this and the persistent presence of maritime patrol aircraft over the approaches to Taiwan will likely have a vital role in enforcement.

What is of greater concern, therefore, is not a sudden uptick in Chinese air activity serving as a harbinger for war, but the steady erosion of Taiwan’s position in the air and sea, which unmanned technology may yet exacerbate.

The views expressed in this Commentary are the authors’, and do not represent those of RUSI or any other institution.

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Dr Sidharth Kaushal

Senior Research Fellow, Sea Power

Military Sciences

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Sam Cranny-Evans

Associate Fellow

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