When airspace becomes the new front in China-Taiwan rivalry

China has systematically expanded the frequency and scope of People's Liberation Army Air Force (PLAAF) incursions into Taiwan's Air Defense Identification Z...

What Happened

China has systematically expanded the frequency and scope of People's Liberation Army Air Force (PLAAF) incursions into Taiwan's Air Defense Identification Zone (ADIZ) as a calibrated coercion strategy.
PLA aircraft logged over 4,000 ADIZ entries in the first nine months of 2025 — more than in any comparable prior period — before Beijing strategically reduced incursion frequency in late 2025 and early 2026 to lower US-China tensions.
Drone encirclements of Taiwan — where unmanned aircraft circumnavigate the island — emerged as a distinct tactical escalation, increasing from 3 instances in 2024 to at least 8 in the first months of 2025 alone.
The PLA has shifted emphasis from daily gray-zone sorties toward intensive inter-service joint-operations training, repurposing assets from harassment missions to war-fighting readiness.
Beijing's ADIZ strategy is described as deliberately "calibrated" — escalating or de-escalating in response to political triggers such as high-profile Taiwan events, foreign arms sales, or US-China diplomatic contacts.
Taiwan's room for strategic manoeuvre is narrowing as the median line of the Taiwan Strait — an informal boundary respected for decades — has been progressively eroded by PLA crossings since 2020.

Static Topic Bridges

Air Defense Identification Zone (ADIZ): Concept and Legal Status

An Air Defense Identification Zone is a designated airspace beyond a nation's territorial boundary within which all aircraft are required to identify themselves and submit to monitoring. ADIZs extend into international airspace and have no basis in binding international law; they derive from customary state practice rather than a treaty framework.

The legal foundation for airspace sovereignty exists only up to the limit of national territory; territorial airspace is sovereign, while international airspace beyond is governed by the Chicago Convention on International Civil Aviation (1944), which enshrines freedom of overflight.
Taiwan's ADIZ was established by the United States Armed Forces in 1954, when the US held responsibility for Taiwan's air defense; a notional "median line" was drawn in 1955.
China has never formally recognised Taiwan's ADIZ; Beijing declared its own ADIZ over the East China Sea in November 2013, overlapping with Japan's and South Korea's ADIZs.
Entry into an ADIZ is not a violation of international law — only violation of sovereign territorial airspace (extending 12 nautical miles from a coast) constitutes an internationally recognised infringement.

Connection to this news: Beijing's ADIZ incursions are legally ambiguous but politically and strategically potent — they normalise PLA presence in airspace adjacent to Taiwan, degrade Taiwan's air defense response cycles, and impose economic and operational costs without triggering the threshold for a legally recognised armed attack.

Gray-Zone Warfare and Hybrid Coercion

Gray-zone warfare refers to a spectrum of state actions below the threshold of open armed conflict but above normal peacetime competition. It typically combines military signalling, economic leverage, information operations, and covert activities to achieve political objectives while avoiding direct escalation.

The concept was elaborated in US strategic doctrine following PLA activities in the South China Sea from 2010 onward, including island reclamation, maritime militia operations, and ADIZ incursions.
Key features: deniability, gradualism, norm erosion, and the exploitation of adversary hesitation to invoke collective defense mechanisms.
Taiwan's specific vulnerability: it cannot invoke Article 5 of NATO or a formal mutual defense treaty, relying instead on the ambiguous US Taiwan Relations Act (1979) for security assurance.
China's gray-zone toolkit around Taiwan includes ADIZ incursions, maritime militia deployments, cyberattacks on infrastructure, economic coercion, and diplomatic isolation.

Connection to this news: The ADIZ intrusion pattern — scaling up or down in response to political signals — is a textbook gray-zone calibration: Beijing uses it to signal displeasure, test response thresholds, and gradually shift what is considered "normal" in the Taiwan Strait without triggering formal conflict.

Taiwan Strait: Strategic Geography and the Median Line

The Taiwan Strait is a roughly 180-kilometre-wide waterway between mainland China and Taiwan. The "median line" — an unofficial demarcation approximately equidistant between both shores — was observed by both the PLA and Taiwan as a de facto buffer zone from the 1950s until around 2020, when China began systematically violating it.

The Taiwan Strait lies within the exclusive economic zones (EEZs) of both Taiwan and China, but is international waters; naval and air transit is unrestricted under the UN Convention on the Law of the Sea (UNCLOS).
The median line's erosion began notably after US House Speaker Nancy Pelosi's visit to Taiwan in August 2022 (Operation Joint Sword), following which the PLA conducted large-scale exercises breaching the line routinely.
Taiwan maintains a defense budget of approximately $18.2 billion in 2026, representing around 2.5% of GDP — under US pressure to increase it further.
The US Taiwan Relations Act (1979) commits the US to provide Taiwan with defensive arms and to "maintain the capacity of the United States to resist any resort to force" that would jeopardise Taiwan's security, without explicitly guaranteeing military intervention.

Connection to this news: The median line's progressive erosion and the normalisation of ADIZ incursions represent linked dimensions of the same strategy: shrinking the geographic and operational buffer available to Taiwan before any military contingency.

People's Liberation Army Air Force (PLAAF): Capabilities and Doctrine

The PLAAF is the air arm of China's People's Liberation Army, ranked among the world's top three air forces by size. It operates under a doctrinal shift from "territorial air defense" to "offensive air operations," enabling power projection well beyond China's borders.

PLAAF assets used in Taiwan ADIZ operations include: J-16 multirole fighters, H-6K/N strategic bombers (nuclear capable), Y-8/Y-9 electronic warfare aircraft, and BZK-005 and TB-001 drones.
The PLA established the Strategic Support Force in 2015 (reorganised into three separate commands in 2024) and the Rocket Force as separate services, integrating air-sea-space-cyber operations.
PLA aircraft conducted 3,615 flights into Taiwan's ADIZ in 2024, more than double the 1,669 recorded in 2023.
Monthly average after May 2024: over 300 PLA aircraft sorties per month in Taiwan's ADIZ, exceeding double the prior two-year monthly average.

Connection to this news: The tactical shift from daily gray-zone sorties to joint-operations training signals that the PLAAF is using the Taiwan theater not merely for political signalling but to build genuine military readiness for a potential contingency operation.

Key Facts & Data

Taiwan's ADIZ established: 1954 (by US Armed Forces); median line drawn: 1955.
PLA ADIZ incursions in 2024: 3,615 flights (more than double 2023's 1,669).
PLA ADIZ incursions, first 9 months of 2025: over 4,000 aircraft entries.
Post-May 2024 monthly average: over 300 PLA sorties per month into Taiwan's ADIZ.
Drone circumnavigation of Taiwan: 3 instances in 2024; at least 8 in early 2025.
Taiwan's 2026 defense budget: approximately $18.2 billion (~2.5% of GDP).
China's East China Sea ADIZ declared: November 2013.
Taiwan Relations Act (US): enacted 1979; provides defensive arms and security assurance without explicit mutual defense guarantee.
Chicago Convention on International Civil Aviation: 1944 — governs freedom of overflight in international airspace.