US-China Clash Regarding The Regime For Passage Through The Taiwan Strait – Analysis


On March 31 two People’s Liberation Army Air Force fighter jets deliberately crossed the median line of the Taiwan Strait and, despite repeated warnings from Taipei’s military, flew 43 nautical miles into Taiwan’s airspace. This was the first such crossing in nearly two decades and was probably response to the increasing US political support for the DPP/Tsai Ing-wen government in the face of Beijing’s more assertive posture toward Taipei. But it was also likely a manifestation of a creeping clash of legal positions between Beijing and the U.S. regarding the regime for passage of warships and warplanes through the Strait. This legal controversy has potentially dangerous practical implications.

The median line has existed since 1955 when it was declared by General Benjamin Davis, then the Commander of the US 13th Air Force then based in Taipei, as part of the ‘rules of engagement’. There was no formal agreement and Beijing has not officially recognized it because in its view Taipei is an inalienable part of its territory.  Nevertheless the median line has in practice served to separate the two sides and their military activities.

In Taipei’s eyes the intrusion into what it considers its airspace was no accident but  rather a “blatant destruction of the status quo in the Strait.” Indeed it may well have been an expression of Beijing’s jurisdiction over the Strait. The move drew a rebuke from the U.S. as well.

According to the UN Convention on the Law of the Sea (UNCLOS), all ships and aircraft enjoy the right of transit passage in straits used for international navigation between one part of the high seas or an exclusive economic zone (EEZ) and another part of the high seas or an EEZ.  Transit passage is the exercise of the freedom of navigation and over flight solely for the purpose of continuous and expeditious transit.  Transit passage cannot be hampered, impeded or suspended.   But UNCLOS also qualifies that right by stating that “if the strait is formed by an island of a State bordering the strait and its mainland, transit passage shall not apply if there exists seaward of the island a route through the high seas or through an EEZ of similar convenience …”. 

Beijing apparently claims that according to this provision the right of transit passage does not apply to the Taiwan Strait and that warships in particular should use the alternative route “of similar convenience” through the Luzon Strait between the island of Taiwan and the Philippines.  Moreover, in its interpretation of the One China Policy it claims that all the waters in the Strait are under ‘China’s’  jurisdiction and comprise its internal waters, territorial seas and its EEZ.

The US Navy claims that the waters in the Strait are “international”. According to the then-commander of U.S. Pacific Command, Admiral Timothy Keating during an official visit to China in 2008, “We don’t need China’s permission to go through the Taiwan Strait. It’s international waters. We will exercise our free right of passage whenever and wherever we choose, as we have done repeatedly in the past and we’ll do in the future.”

However, there is no such legal regime as “international waters”. Apparently what the U.S. legally claims is high seas freedom of navigation and over flight for all vessels and aircraft including military vessels and aircraft through the Strait regardless of whether it is Beijing’s EEZ or Taiwan’s EEZ. To it, such freedom of navigation and over flight includes related activities such as anchoring; launching and recovery of aircraft and water craft; other military devices; intelligence, surveillance and reconnaissance activities; exercises; maneuvers; and ‘military surveys’. 

Both China and the U.S. are increasingly backing up their conflicting interpretations of UNCLOS with provocative and dangerous military actions as evidenced by the recent near-miss between their warships. Indeed, the stepped up US warships transits of the Strait—about once a month since October 2018 from one a year at most- -can be interpreted as a demonstration of this claim – and Beijing’s provocative crossing of the median line can be considered a response thereto.

But in addition to arguing that warships should use the Luzon Strait instead of the Taiwan Strait, Beijing also claims certain restrictions on the activities of warships in its EEZ including that in the Strait.  This U.S. –China dispute translates in practice as to whether or not China can set conditions for the passage of vessels through its EEZ in the Strait. While these differences have yet to come to the fore there, they have resulted in international incidents elsewhere in Beijing’s claimed EEZ.

These differences are again based on their respective interpretations of relevant provisions of UNCLOS  –  –  which the U.S. has not ratified.  Despite the U.S. position to the contrary, the UNCLOS EEZ  regime does have some restrictions on freedom of navigation such as the duty to pay “due regard” to the rights of the coastal state including not violating its marine scientific research consent and environmental protection regimes or threatening its security.   Other UNCLOS terms that pertain to freedom of navigation in the EEZ—and whose meaning is disputed include “abuse of rights,”  “peaceful use/purpose,”  “marine scientific research” , and “other internationally lawful uses of the sea”.

China is not alone in its interpretation that there are limits to freedom of navigation in its EEZ.  Some 17 other states also claim some restrictions on military activities in their EEZ including in Asia, Bangladesh, India, Malaysia, Myanmar, Pakistan and US ally Thailand.

They argue that UNCLOS was a “package deal,” and that non-ratifiers of the Treaty like the U.S. cannot credibly or legitimately pick and choose which UNCLOS provisions they wish to abide by and unilaterally interpret them to their benefit.  They say this is especially so regarding the EEZ regime which was created de nouveau by the Treaty.

Tensions in the Taiwan Strait – between Beijing and Taipei – and between Beijing and Washington – – are clearly on the boil and are being driven by a myriad of factors.  But the creeping confrontation of contrasting interpretations of the applicable navigation regime for military vessels and aircraft in the Strait could be the straw that breaks the camel’s back.

Another version of this piece first appeared in the South China Morning Post.

Mark J. Valencia

Mark J. Valencia, is an internationally known maritime policy analyst, political commentator and consultant focused on Asia. He is the author or editor of some 15 books and more than 100 peer-reviewed journal articles. He is currently an Adjunct Senior Scholar, National Institute for South China Sea Studies, Haikou, China.

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