Julian Ku at Opinio Juris notes that while much of the foreign policy community is focused on the Iran deal, China has undertaken a significant political escalation of its dispute with Japan over the Senkaku (or Daioyu) Islands, by invoking a so-called Air Defense Identification Zone (ADIZ) around the disputed islands. The Wall Street Journal and other newspapers reported on it yesterday, noting criticism from both Washington and Tokyo; the response from Beijing, Julian adds, is for the US to mind its own business. The WSJ quoted a “senior U.S. official” saying Sunday that there would likely be a demonstration of American military resolve to continue operating in the area of the islands without Chinese interference. The unspecified display, added the Journal’s story, “isn’t likely to involve a direct military confrontation.”
That demonstration came Monday night in the form of two US military aircraft, on what the Defense Department described as long-scheduled training mission, according to NBC news:
“We will not in any way change how we conduct our operations,” Pentagon spokesperson Col. Steve Warren said, adding that the U.S. maintains that the newly expanded ADIZ is in international waters. Monday evening ET, two B-52 bombers took off from Anderson Air Force Base in Guam as part of an ongoing training exercise called Coral Lightning Global Power Training Sortie. The bombers were in the ADIZ for less than one hour, Warren said. This was a “long-planned training exercise,” and the U.S. did not inform the Chinese of their flight plan, Warren said. The flights occurred without incident, Warren said, adding that there was no reaction, no Chinese aircraft were spotted in the air, and the Chinese did not contact the U.S. military about the flight.
What’s an ADIZ? Speaking loosely, it’s a zone of airspace beyond a coastal state’s national borders projected into the ocean, in which the state asserts the the right to require, at its option, identification, flight plans, radio contact, air traffic control, or other measures, of (certain) aircraft entering the zone (with intentions to enter the national airspace). The concept is not laid out in any treaty, although there is extensive state practice by a variety of states, including the United States. The rationales for maintaining ADIZ include national security, air traffic safety, anti-smuggling, among others.
There’s a policy tension here for the United States, as Peter A. Dutton (a professor at the US Naval War College) notes in an excellent 2009 article in the American Journal of International Law, “Caelum Liberam: Air Defense Identification Zones Outside Sovereign Airspace.” On the one hand, the US maintains five ADIZ, covering the largest non-sovereign airspace of any state. US domestic law regulates ADIZ in some considerable detail – setting out, for example, what some categories of aircraft are required to do on entering such a zone. (See, e.g., Title 14, Code of Federal Regulations section 99.9.)
On the other hand, although the US has come to accept the international law trend of the past few decades and enshrined in the Law of the Sea Convention, giving international law permission for coastal states to establish “exclusive economic zones” (EEZ) for control and exploitation of resources beyond the traditional territorial waters of twelve nautical miles, the US continues to assert traditional navigation rights of passage (and airspace passage) even within those EEZs, up to the limit of territorial waters that enjoy complete national sovereignty. To these ends, for decades the US Navy has undertaken a formal Freedom of Navigation Program, under which US ships systematically transit straits and other places where free passage (of the ships of any nation, not just the United States) might be contested. Freedom of the high seas includes transit of the airspace above it as well. The US has been willing to use military force to ensure the freedom of navigation – for example, against Libya’s claim, starting in 1973 and stretching into the 1980s, to declare the Gulf of Sidra fully territorial waters and closed to free passage. In 1986, the US sent three warships into the Gulf of Sidra as part of a declared Freedom of Navigation Operation to ensure the rights of all nations to use these waters and airspace above. Libya fired on the vessels and the US responded with missile strikes.
These two US government policy aims are not necessarily inconsistent with each other. But they do have a built-in policy tension, depending on the stringency of particular regulations applied in the ADIZ – they run the risk that the US might impose more stringent regulation in its declared ADIZ than it would accept for its own aircraft in some other state’s ADIZ. The State Department’s position in Secretary Kerry’s brief initial response to China’s ADIZ announcement, therefore, seemed aimed at showing that US ADIZ policies were consistent with US freedom of navigation views and that the US government’s position was, so to speak, sauce for the goose – the same for it as for other states. Although an ADIZ is not per se impermissible, the State Department said, the US government does
not support efforts by any State to apply its ADIZ procedures to foreign aircraft not intending to enter its national airspace. The United States does not apply its ADIZ procedures to foreign aircraft not intending to enter U.S. national airspace. (Emphasis added)
The language of 14 CFR 99.9, Dutton notes in a close reading of these regulations, draws a somewhat different distinction, however. This regulation refers to “civilian aircraft” as falling under US ADIZ procedures, but not foreign state or military aircraft. (Dutton notes that subsequent CFR sections drop the “civilian” in favor of “aircraft,” however, raising a potential question as to its meaning.) This might seem somewhat counterintuitive – one might think that the aircraft a coastal state would most want to follow its ADIZ procedures would be foreign military aircraft, not civilian jetliners. As one US Navy officer explained to me, however, the US insists that states, including the United States, can fly military aircraft unannounced, on intelligence gathering or other missions, right up to the 12 nautical mile territorial limit, so long as the intent is remain in international airspace and not to enter foreign sovereign airspace. Dutton sums up the US position this way:
[T]he US Department of Defense clearly asserts the right of US military aircraft to fly abroad through ADIZs without complying with coastal state regulations so long as the US aircraft does not intend to enter the coastal state’s national airspace and is not otherwise engaged in controlled flight.
The US thus insists on its legal right to do so, and accepts that other states will do the same – and they do. Russian aircraft, for example, routinely conduct missions within US ADIZ without pre-announcement, just as the US does. The US does not demand that they comply with ADIZ regulations; instead, the US reserves the option to send up aircraft as escorts, monitoring the foreign military aircraft, but not challenging their presence. Scrambling military jets for unannounced civilian aircraft transiting the ADIZ is much less useful (dangerous and crazy, I was told) than requiring that they provide information on their status and follow directions – at least, as the State Department statement says, if they are intending to enter the national airspace, in which case matters of identification, destination, air traffic control, national security, and other sovereign concerns matter. Failure by a civilian jetliner to comply cannot be met with force in the air, under international air traffic treaties; there are many avenues of recourse from fines and sanctions by national air traffic regulators to diplomatic actions, and dwelling on doomsday, ticking-airliner-timebomb scenarios is a dangerous distraction from the complex realities of the international airspace. Of course, there can be questions as to whether a foreign aircraft (civilian or military) intends to enter the national airspace, of course; likewise there can be breaches of national airspace that are innocent because unintentional. And something can always go wrong, particularly when brinksmanship is involved as a political policy of a state, such as the mid-air collision of US and Chinese aircraft in April 2001.
China’s assertion of an ADIZ, as Julian Ku says, is not per se impermissible. But the devil is in the details. China’s ADIZ raises two large questions of legality. First, the “not-impermissible” scope of an ADIZ, that which is accepted in widespread state practice, is a projection outwards from the coastline of a coastal state. One might argue as a matter of international law as evidenced by state practice that a ADIZ has to bear a reasonable relationship to that coastline and the protection of its sovereignty, in the sense of both national security and domestic regulation (e.g., air traffic management, anti-smuggling, etc.). Those requirements can be fluid, addressing the nature of technology and threats to sovereignty, while still being “reasonably” connected to the protection of the sovereign coastline from unlawful encroachment.
Whatever can reasonably be projected as an ADIZ related to the coastal state’s coastline, the legality of an ADIZ created in such a way as to allow China to assert a new legal claim regarding contested rocks far out at sea has to be considered at issue. It’s a “bootstrapping” claim, assuming its conclusion: China declares an ADIZ around a contested territory, and then uses that as a basis to control the airspace as though it were an ADIZ declared along its uncontested home coastline. But an ADIZ cannot create sovereign territory or vindicate a claim to it. Unfortunately, enforcing that fundamental point requires that other states ignore and denounce the ADIZ – in the teeth of a threat, implied or express, that whatever regulatory terms China has dictated (see below) will be enforced.
Whereas it seems clear that state practice is limited to uncontested home territory. No bootstrapping. The virtue of an ADIZ is that it can reduce risks of confrontation, mistake, and dangerous brinksmanship as aircraft come close to unquestionably sovereign, territorial airspace by regularizing the passage of civilian aircraft, especially, as either intending (in which case ADIZ procedures apply) or not intending to enter the sovereign’s airspace (in which case ADIZ procedures do not apply) is turned into a mechanism for contesting sovereignty, and becomes a pretext for confrontation.
Second, beyond the legal ability to establish an ADIZ around a contested rock far away from the undisputed home coastline, the regulations that China set out in its official ADIZ declaration raise a serious legal question as to whether an ADIZ even can require such things of foreign aircraft that do not intend to enter China’s territorial airspace. According to the declaration’s “third rule,” aircraft
flying in the East China Sea Air Defense Identification Zone should follow the instructions of the administrative organ of the East China Sea Air Defense Identification Zone or the unit authorized by the organ. China’s armed forces will adopt defensive emergency measures to respond to aircraft that do not cooperate in the identification or refuse to follow the instructions.
This is highly destabilizing. It does not appear compatible with state practice. It refers to “aircraft,” without any distinction between civil and military aircraft, or between aircraft intending to enter China’s (incontestably) sovereign airspace and those that do not. It covers an immense area of ocean. Combined with a threat to adopt “defensive emergency measures” with regards to aircraft that “do not cooperate” or “refuse to follow the instructions,” this is politically a highly provocative move and one of dubious legality, even considered under a standard of plausible interpretation of state practice of ADIZ. The State Department statement recognized this; it added, “We urge China not to implement its threat to take action against aircraft that do not identify themselves or obey orders from Beijing.”
The real test of China’s provocation is not the US flying military aircraft through the ADIZ without prior notice, of course, as it has already done. It’s all about Japan, the next time it sends its F-15s to overfly the disputed islands – which of course it will have to do and presumably soon. The US government will almost surely have to make more and stronger statements, and it will probably do well to analyze state practice on both of these issues – ADIZ over disputed territorial areas, and ADIZ regulations that do not distinguish between the intentions and missions of different aircraft flying in international airspace. The US perhaps needs to review, if it hasn’t done so already, its own regulations and their application to ensure that in actual practice, they in fact distinguish between aircraft intending to enter US national airspace and those that don’t, and so conform to what the State Department said is the US government’s view.
The larger issue, of course, is the extent to which the US has brought this upon itself and its Asian Pacific allies by sending signals, during the first two Obama years, especially, that it no longer proposed to act as a stabilizing hegemon that framed everyone else’s actions around the gains to be had from acting within the status quo. No doubt a rising China would always have made moves to challenge Japan and other Asian powers, and not doubt a rising China would always have made moves to challenge US hegemony in the Pacific; but uncertainties about US will and commitment have raised the stakes considerably (as I discuss in considering hegemony in Chapters 2 and 3 of my 2012 book, Living with the UN). Hegemonic credibility is easier to erode than rebuild, as the Obama administration is learning.
(Additionally, there has been some talk as to whether unmanned military drones that, according to some news reports, might be put up by Japan or China over the disputed islands would tend to ratchet up the possibilities of a military incident that spirals out of control, or tends to ratchet it down; Matthew Waxman and I will post something soon on that specific issue; it seems to us context-specific and not easily predicted in advance, though one can still say some useful things about the strategic logic of shifting to unmanned military drones as a form of signaling behavior.)
Meanwhile, comments to Julian Ku’s post at Opinio Juris are quite expert and useful. The eminent Australian law of war scholar Ian Henderson, for example, observes with respect to the legality of this particular ADIZ (my comments on the legality of China’s ADIZ essentially track Henderson’s points):
[T]here are two different issues at play. The first, the declaration of an ADIZ. The second, the ‘rules’ associated with that ADIZ. Based on state practice, it is pretty clear that a State can declare an ADIZ in appropriate circumstances. However, as the rationale for an ADIZ is to protect national security, there is arguably a difference between declaring an ADIZ adjacent to the mainland or an occupied island, and declaring one adjacent to a mere rock. Of course, an ADIZ adjacent to the mainland that extends for over 100 or more nautical miles might also cover unoccupied rocks. However, such an ADIZ could not overlap another State’s national airspace — athough it could overlap another State’s ADIZ. Even though the declaration of a particular ADIZ might be lawful, the second issue is the rules associated with the ADIZ. Perhaps the most important issue is that an ADIZ cannot affect freedom of navigation in international airspace. For example, it cannot impose operating restrictions on state aircraft beyond flying with due regard.
(Note: I have rewritten and extended this post considerably from its original version.)