In the aftermath of Taiwan’s January presidential and legislative elections, the world wondered what sorts of responses Beijing would have to another victory by the Democratic Progressive Party (DPP, 民進黨) after Lai Ching-te (賴清德) was elected president. Predictably, Chinese Communist Party (CCP) officials quickly condemned the election, and issued warnings against “Taiwan independence” and “separatist” forces. At the same time, observers drew attention to Chinese military aircraft flying across the median line of the Taiwan Strait, which was an expected response since these incursions occur on a near-daily basis. Another major development was Nauru’s decision to sever ties with Taipei in favor of Beijing, which was announced just two days after the elections. While undoubtedly painful for Taiwan, the switch was not particularly shocking, as Beijing has been poaching Taiwan’s remaining diplomatic allies ever since Tsai Ing-wen (蔡英文) was elected president in 2016. Though each of these developments upset the delicate cross-Strait status quo in varying ways and to different degrees, anyone following cross-Strait relations could have predicted these post-election responses to a DPP presidential victory.
The one post-election, cross-Strait development that received less of a spotlight was the Civil Aviation Administration of China’s (CAAC, 中國民用航空局) unilateral announcement of new civil aviation flight paths within the Taiwan Strait. Taipei immediately condemned the announcement after it was revealed that the CAAC moved one route to under five miles from the median line of the Taiwan Strait, while others are close to Taiwan’s own civil flight routes for its outlying islands of Kinmen and Matsu. The decision to further expand and relocate these flight routes should not come as a major surprise, as the CAAC has gradually expanded these routes since 2015, when they were first established.
This development is more important—and likely more detrimental to the cross-Strait status quo—than the previously mentioned post-election incidents, as the expansion of flight routes M503, W122, and W123 will result in a significant increase in Chinese civilian aviation in the Taiwan Strait. Such a move diminishes Taiwan’s ability to assert its own sovereignty in the area, and normalizes the civil element of Beijing’s salami-slicing tactics against Taiwan.
Image: A graphic from Taiwan’s Civil Aeronautics Administration showing flight routes around Taiwan: including the W122 and W123 routes, and the path of the M503 route (pink line). The new M503 route announced by the PRC in early February shifts the de facto M503 flight path further eastwards, six nautical miles closer to the Taiwan Strait center line. (Image source: ROC Civil Aeronautics Administration)
What Exactly Did Beijing Do?
In late January, the CAAC made two key changes to the flight routes in the Taiwan Strait. Focus Taiwan explained these changes in depth in the aftermath of the announcement. First, flight route M503, which operates north-south on China’s side of the Taiwan Strait, was moved six nautical miles east, bringing it considerably closer to the median line of the Taiwan Strait. This flight path was first created in January 2015 (but not utilized until March of that year), with the six-nautical-mile offset included in order to provide an additional buffer from the median line of Taiwan Strait. The addition of the buffer was a conscious decision by Beijing to try to make the creation of the new routes less controversial. That decision provided a concrete example of the greater regard Beijing once showed for the tacit division of the Taiwan Strait. Notably, in March 2015, the route only allowed for northbound flights; there were no southbound flights. Then, in January 2018, the CAAC opened up the route to southbound flights, making it fully functional. Now, with the flight path moved closer to the median line, Beijing has signaled another dimension of its desire to erase the median line.
Second, flight routes W122 and W123, which operate east-west connecting to the north-south M503, opened up to eastbound flights. These routes have a similar history to M503 as they connect to each other. Before the January 2024 announcement, the W122 and W123 routes were limited to only westbound flights (i.e., flights heading into China). The opening of these westbound routes occurred in 2018 after the paths were established in 2015 but never utilized. Now, the route allows for flights heading from the cities of Xiamen and Fuzhou into the Taiwan Strait.
To put it simply, a mere 10 years ago, no planes flew on these flight paths. However, after nearly a decade of incremental growth, China’s civil flight paths in the Taiwan Strait have become a permanent feature of the cross-Strait status quo.
Why Does This Matter?
To the average reader, these developments may not seem like a big deal: who cares about civilian flight paths over a waterway? For Taiwan, however, there are a number of reasons to find this news troubling.
First, the addition of the eastbound flights to the W122 and W123 paths increases traffic close to previously existing Taiwanese civilian flight routes—specifically, flight routes W2, W6, and W8—that connect the outlying islands of Kinmen and Matsu to Taiwan. Having increased traffic making turns so close to Taiwanese flight routes—especially close to airports—significantly increases the potential for an accident or miscommunication. These airspaces are already fraught with the constant incursions by Chinese military aircraft in the same areas. Adding more civilian aircraft into the mix complicates an already tense situation.
Second, Taiwan lacks the ability to voice its concerns about China’s unilateral moves in the relevant international forum: the International Civil Aviation Organization (ICAO). The ICAO is a United Nations-affiliated organization that is the global authority for aviation matters. Since Taiwan lacks membership or even observer status in the UN, it has no guaranteed seat at the table. Under the presidency of Ma Ying-jeou (馬英九), Taipei sat in on ICAO meetings as a part of Beijing’s efforts to maintain a higher level of cross-Strait dialogue. However, Beijing put an end to this practice when Tsai was elected, and the doors to ICAO were shut to Taiwan despite having its own Flight Information Region (FIR), which is one of the busiest in the world. In 2023, Hong Kong-to-Taipei flights represented the third-busiest international flight route in the world.
Lack of access to the ICAO proved to be an issue in in the aftermath of then-US House Speaker Nancy Pelosi’s August 2022 visit to Taiwan, when the People’s Liberation Army (PLA) conducted large-scale exercises and announced no-fly-zones for civilian aircraft in the vicinity of Taiwan. Consequently, Taiwan’s Civil Aeronautics Administration (CAA, 民用航空局) had to rely on its Japanese and Filipino counterparts to divert and reroute flights since ICAO was not an option. In this instance, Taiwan’s exclusion from the UN system created—and will continue to create—issues for aviation safety as cross-Strait tensions continue to deteriorate.
Third, it continues a pattern of leaders in Beijing making unilateral decisions that are not dangerous in and of themselves, but increase the possibility for danger to occur. In this instance, China’s actions heighten the risk of accidents or miscommunications. In 2015, after CAAC announced the creation of these routes, officials from Beijing and Taipei were able to have discussions about the paths, which resulted in Beijing moving route M503 six nautical miles to the west. Those channels no longer exist, and such discussions no longer occur. As a result, there is no prior warning when such unilateral decisions are made: Taiwan finds out about these developments when the relevant Chinese agency makes an announcement.
Given recent issues regarding aviation safety, such as the January 2024 incidents when a Boeing 737 Max 9 “plug” blew off during takeoff and a Japanese aircraft crashed into a coast guard plane during landing, it is deeply concerning when a country makes unilateral decisions related to international aviation safety. In this regard, China’s effort to limit Taiwan’s sovereignty by expanding civil aviation activity in the Taiwan Strait could have major ramifications. Already, the growing lack of clarity in the region has resulted in violence, as demonstrated by the deaths of two Chinese fishermen who were chased off by Taiwan’s coast guard after illegally fishing in Taiwan’s waters. At sea, the costs were somewhat limited, but in the air, the toll could be much, much higher.
Moving Forward
After eight years of essentially spurning all forms of high-level cross-Strait communication, leaders in Beijing find themselves having to deal with another DPP president—one that they distrust even more than Tsai. And since Lai’s election in January, it appears that Beijing has no intention of changing course in its dealings with Taipei. Under Tsai, Beijing worked to squeeze Taiwan on the economic, military, and political fronts in order to limit its international space. These efforts are likely to continue to escalate during Lai’s presidency.
In the air, China’s campaign to place pressure on Taiwan has manifested in the regular aviation incursions into the defense identification zone (ADIZ) near Pratas/Dongsha Island, and the Taiwan Strait itself. The opening up of flight routes in 2018 was also another element on this front. Keeping Taipei out of ICAO meetings complemented these efforts.
For Beijing, increasing civil aviation in the Taiwan Strait likely appears to be a relatively low-risk decision. Expanding the W122 and W123 routes and moving M503 are all fairly unobtrusive, low-profile behaviors that lack the immediacy or bombast of military exercises. The average person will likely not care too much about this—because on the surface, it does not seem like a big deal. However, things like this are not a big deal until they become one. Ultimately, the way that Beijing’s expansion of these civilian flight paths could rise to greater attention is through tragedy, and no one wants that outcome. Furthermore, these new flight paths could set the stage for the CAAC to unilaterally create additional new civilian flights near and around Taiwan as well.
If Beijing ever wants to lower the temperature in cross-Strait relations, it has plenty of small issue areas that it could address with Taipei at a technical level. Senior-level politicians and government officials do not need to get involved in issues like moving or deconflicting flight paths in the Taiwan Strait. Such technocratic conversations among mid-level officials could provide a new beginning for confidence-building mechanisms in a more transparent cross-Strait environment. However, while more dialogue would certainly be welcome, it is unlikely to occur until a real tragedy happens—and that is why Beijing’s unilateral decision to move and expand these flight paths should be of major concern to international actors.
The main point: The recent decision by the Civil Aviation Administration of China to move the M503 flight path closer to the median line of the Taiwan Strait, and to open up eastbound traffic on the W122 and W123 routes, represents another move by Beijing to diminish Taiwan’s sovereignty. Given Taiwan’s exclusion from the United Nations system, it is very limited in its ability to lodge official complaints at the international level. Until Beijing and Taipei can address even these low-level issues, cross-Strait tensions will continue to spiral.
