众所周知，菲律宾在《联合国海洋法公约》项下就南海问题对中国提起了仲裁程序。仲裁庭已就其对菲律宾所提诉求是否具有管辖权作出了裁定。仲裁庭裁定其对该案有管辖权，尽管只对菲律宾所提15项诉求中的3项诉求的管辖权是无条件的。此后，仲裁庭开庭审理了各项诉求的实体问题，并很可能在今年晚些时候作出最终裁决。然而，批判性地研究仲裁庭关于管辖权的裁决，不难发现其中存在很多瑕疵。

首先我们要了解，《联合国海洋法公约》强调，对于南海这种半封闭海域的周边国家，即使它们之间不存在关于海域划界的协议，这些国家也应通过相互合作解决共同面临的问题。

此外，《联合国海洋法公约》明确规定沿海国可以主张的海域范围，包括12海里领海、200海里专属经济区以及至少200海里的大陆架（如果地理条件允许，还可主张超过200海里的外大陆架）。这些海域主张无法基于高潮时没入水中的低潮高地作出，但所有这些主张都可以通过岛屿作出，唯一的例外是“不能支持人类居住或者本身经济生活的岩礁”只能主张领海。“岩礁”这一术语很难解释，迄今也鲜有关于其具体所指的国际法判例。然而，这对菲律宾的诸多论据而言却至关重要，因为菲声称南海的许多地物要么是低潮高地，要么就是“岩礁”。

在《联合国海洋法公约》项下的部分特定情形中，一国有义务就与另一国的争端接受仲裁，但此义务受制于许多重要的例外和限制规定，其中部分规定是可以由当事国自行选择加以适用的。换言之，我们常说缔约国在《联合国海洋法公约》项下同意接受仲裁，但更准确的说法是缔约国仅在《联合国海洋法公约》规定的例外和限制条件下同意仲裁。这一点很重要，因为在通过《联合国海洋法公约》的联合国会议上，《公约》关于争端解决的条款是作为一揽子协议的一部分被接受的。对公约所有缔约国来说，保证一揽子协议不受干扰显然极为重要。

当菲律宾在《联合国海洋法公约》项下提起仲裁程序时，中国拒绝出庭，并认为该程序是被《公约》规定的例外情形之一所排除的。在国际司法程序中，一国不出庭的做法其实并不少见。最著名的案例是在尼加拉瓜于上世纪80年代在国际法院对美国提起的诉讼中，在法院作出具有管辖权裁定后，美国即拒绝继续参与。

那么，仲裁庭是基于何种理由认为其具有管辖权呢？首先要注意的是，尽管南海诸岛的领土主权这一充满争议的问题牵涉中国、菲律宾、越南、马来西亚和文莱等多个国家，但是仲裁庭对领土主权事项并没有管辖权。换句话说，仲裁庭不能裁定某一地物属于中国还是菲律宾。这是因为仲裁庭只对关于《联合国海洋法公约》“解释或适用”的争端具有管辖权，而《公约》不能用来解决领土争端。菲律宾认识到这一困难并明确表示其无意要求仲裁庭对领土主权问题作出裁定。

尽管如此，仲裁庭认为即使不能裁定地物归属于哪国，其仍可判定南海地物的地位（即这些地物是“岩礁”还是低潮高地）。我在别处曾指出，将判定地物的地位放在决定主权事项之前，是本末倒置的，而且国际司法程序中从未出现过类似先例。

为作出其具有管辖权的结论，仲裁庭试图探究菲律宾提起此案的“真正问题”，并认定这一“真正问题”不是地物的主权而是地物的地位。因此，仲裁庭声称可以在不触及地物主权问题的情况下裁定地物地位问题。然而，在最近的毛里求斯诉英国案中，毛里求斯在《联合国海洋法公约》项下就英国宣布在查戈斯群岛周边区域设立海洋保护区的效力问题提出质疑，毛里求斯的实际目的则是请求仲裁庭就这些岛屿的主权问题作出裁定。仲裁庭在该案中正确地看穿了毛方的把戏，拒绝在这一问题上接受毛方的论证。但让人不解的是，南海仲裁案仲裁庭却并未遵循上述先例。

同样需要注意的是，中国援引的《联合国海洋法公约》中的例外规定之一即有关海域划界问题。根据这一规定，其他国家不得就涉及中国的海域划界的问题提起强制仲裁。但实际上，划界海域范围内的诸多地物的地位是什么，这是关于任何海域划界的核心问题之一，因为低潮高地不产生任何海域，而“岩礁”仅仅具有领海。因此，确定海洋地物的地位是进行海域划界必不可少的要素之一。换句话说，划定海域界限必须包括且应当考虑海洋地物的地位。这样来看，一个有力的观点是，海域划界应当包括作为海域划界不可分割一部分的海洋地物地位的认定，这一问题也属于中国作出排除的例外事项。

同时，大家都熟知“陆地统治海洋”这一法律原理。换句话说，一国基于其陆地领土而拥有海洋权利。因此，国际法院在其判例中总是在裁定海域划界事项前先解决陆地领土争端。这里有三项独立的要素：地物的地位、海域划界以及陆地领土的主权。尽管仲裁庭接受自身对后两项要素不具有管辖权的事实，却依然裁定基于对第一项要素具有管辖权而继续审理此案。

大家可能会思考仲裁庭以此方式继续审案是否正确。国际法院在一些案件中强调必须维护司法完整性。本案中，仲裁庭认为其在不能就作为前提而且不可分割的海域划界和领土主权要素作出裁定的情况下，也能够对地物地位这一要素作出裁定。仲裁庭在此基础上试图行使管辖权，我们同样也可以质疑其是否维护了司法完整性。

中国一直主张关于南海的任何争端均应通过当事方谈判解决，而不是诉诸司法程序。在此背景下，中国指出其与包括菲律宾在内的东盟国家于2002年签订的《南海各方行为宣言》明确提及此点。诸如《宣言》这样的文件本身可能并不具有正式的法律拘束力，但对国际法学者来说，它们通常应被视为作出了禁止反言的意思表示。因此，在A国向B国作出表态，B国依赖该表态，而且一旦A国违反该表态则B国将受损的情况下，A国不能背弃这一表态。但在本案中，仲裁庭认为《宣言》不构成菲律宾的这种声明。这实在难以理解：《宣言》是各方共同谈判的文件，并由高层官员签署，认为这不构成声明实在很奇怪。但结果是，仲裁庭允许菲律宾撤销其在《宣言》中所作表态并继续参与仲裁。这将可能成为一个恶例：目前各国正在就数以万计这类可能无法律拘束力的文件进行谈判，但各国都认为应当遵守这类文件中的规定。仲裁庭作出的上述裁定可能撼动国际关系整体的稳定性。

最后，在《联合国海洋法公约》项下，仲裁庭有义务确保案件在开庭前“有充分依据”。本案中的一位法官在先前的案件中曾将此要求比喻为普通法系国家在刑事案件中适用的“消除合理怀疑”标准，这当然是一个严格的标准。但问题的症结是，仲裁庭在裁定其对菲律宾诉求具有管辖权时是否也适用了这一高标准。

As is now well known, the Philippines has brought arbitration proceedings against China under the United Nations Convention on the Law of the Sea (UNCLOS) relating to the South China Sea, and the Tribunal has recently given its decision on whether it has jurisdiction over the claims made by the Philippines. It found that it had jurisdiction, although unconditionally only over three of the fifteen submissions made by the Philippines. The Tribunal has since heard argument on the merits of the various claims, and is likely to give its ruling on them later this year. But looked at critically the decision of the Tribunal that it has jurisdiction has a number of weaknesses.

As background, UNCLOS emphasises that the States bordering a semi-enclosed sea, like the South China Sea, should cooperate together in dealing with common issues, even when there is no agreement about the maritime boundaries between them.

In addition, UNCLOS sets out what maritime zones it is permissible for a coastal State to claim: a territorial sea of twelve nautical miles, an exclusive economic zone of 200 nautical miles, and a continental shelf stretching at least to 200 nautical miles, but potentially extending beyond that if the geological conditions are right. These maritime zones cannot be claimed from “low-tide elevations”, that is features which are underwater at high tide. All of these maritime zones can be claimed from islands, except that “rocks which cannot sustain human habitation or economic life of their own” can only generate a territorial sea. This definition of “rocks” is not easy to interpret and so far there has been little international case-law on what it might mean. However, it is critical to many of the arguments of the Philippines that they allege that a large number of the features in the South China Sea are either low-tide elevations or “rocks”.

Under UNCLOS there are certain circumstances in which a State is obliged to accept that a dispute with another State can be put to arbitration, but there are a significant number of exceptions and limitations to this obligation, some of which are exercisable at the option of the State concerned. In other words, when it is said that under UNCLOS the States party have consented to arbitration, this is true only in a very qualified way: they have only consented to arbitration subject to the exceptions and limitations set out in UNCLOS. This is important because the provisions in UNCLOS on the settlement of disputes were accepted as part of a package deal at the UN Conference which adopted UNCLOS; it is obviously important to all parties to UNCLOS that the package deal is not disturbed.

When the Philippines commenced arbitration proceedings under UNCLOS, China declined to appear, arguing that the proceedings were covered by one of the exceptions in UNCLOS. Non-appearance by a State in international proceedings is actually not so unusual. Most famously, the United States declined to participate in the proceedings brought by Nicaragua in the International Court of Justice in the 1980s after the Court had held that it had jurisdiction.

So, on what basis did the Tribunal find that it had jurisdiction? The first point to note is that the Tribunal does not have jurisdiction to adjudicate upon the territorial sovereignty over the various land features in the South China Sea – even though it is common knowledge that this issue is hotly disputed, not only by China and the Philippines, but also by Viet Nam, Malaysia and Brunei. In other words, the Tribunal cannot say that a particular feature belongs to China or the Philippines. This is because the Tribunal only has jurisdiction to decide on disputes over the “interpretation or application” of UNCLOS, and UNCLOS of course is not concerned with resolving disputes over land territory. The Philippines recognised the difficulty here and expressly denied that it was seeking a decision on sovereignty over land territory.

Despite this, the Tribunal took the view that it can decide upon the status of features in the South China Sea (ie whether they are “rocks” or low-tide elevations), even though it cannot rule on which State the feature belongs to. I have described this elsewhere as putting the status cart before the sovereignty horse, and there appears to be no precedent for an international tribunal proceeding in such circumstances.

In reaching this conclusion, the Tribunal asked itself what was the “real issue” in the case brought by the Philippines, and decided that it was not about the sovereignty over the features, but about their status; thus, it said that it could rule on the latter question without touching on the former. This is despite the recent precedent of the case brought by Mauritius against the United Kingdom, in which by bringing proceedings under UNCLOS questioning the validity of the marine protected area declared around the Chagos Archipelago, Mauritius sought to dispute the sovereignty over the islands. The Tribunal in that case rightly saw through that device and declined to accept Mauritius's argument on this point. It is perhaps surprising that the Tribunal in the Philippines case did not follow this precedent.

It is also important to note that one of the exceptions in UNCLOS which China has made use of relates to maritime delimitation. Thus, there can be no compulsory recourse to arbitration in a case about maritime delimitation involving China. But actually one of the key questions in any maritime delimitation is: what is the status of the various features in the maritime area being delimited. This is because, as we have seen, low-tide elevations do not generate maritime zones at all and “rocks” only generate a territorial sea. So, deciding upon the status of maritime features is an indispensable component in effecting a maritime delimitation. In other words, delimiting a maritime boundary necessarily involves also considering the status of maritime features. There is a strong argument therefore that the Chinese exception for maritime delimitation should also have been held to cover the question of the status of the maritime features which are an indispensable part of effecting a maritime delimitation.

Furthermore, there is a well-known legal dictum that “the land dominates the sea”. In other words, a State's entitlements to maritime zones depends upon the territory owned by that State. Thus, the International Court of Justice in its case-law has always decided upon disputes over land territory before proceeding to prescribe a maritime boundary. So, there are three interdependent elements: the status of features, maritime delimitation and sovereignty over land territory. But even though the Tribunal accepted that it has no jurisdiction over the latter two elements, it has decided to proceed with the case on the basis that it has jurisdiction over the first element.

One wonders whether it was right for the Tribunal to proceed in this way. The International Court of Justice has emphasised in several cases that it must protect the integrity of its judicial function. In the same way, it is legitimate to ask whether the Tribunal can be said to be acting with due judicial integrity when it seeks to exercise jurisdiction on the basis that it can rule on one element of a case, but not on two prior and indispensable elements of that case.

China has always maintained that any disputes concerning the South China Sea should be settled by negotiation between the parties, rather than through recourse to judicial procedures, and in this respect it points to the Declaration on the Conduct of Parties in the South China Sea, signed by China and ASEAN (including the Philippines) in 2002, which states this explicitly. A document like the Declaration may not be formally legally binding in itself, but to international lawyers it would normally be regarded as giving rise to what is called an estoppel. This is where State A makes a representation to State B, which State B relies upon to its detriment; in such circumstances, State A cannot go back on its representation. But in this case the Tribunal held that the Declaration did not amount to a representation by the Philippines. This is very difficult to understand: the Declaration was a jointly negotiated document, which was signed at a high level, so to say that it does not constitute a representation seems odd. But the result was that the Tribunal allowed the Philippines to resile from what had been said in the Declaration and to proceed with the arbitration. This may be an unfortunate precedent: there are many tens of thousands of similar documents negotiated between States, which may not be legally binding, but which States feel they ought to abide by; the Tribunal's decision is therefore potentially destabilising in international relations generally.

Finally, under UNCLOS, the Tribunal is obliged to ensure that a case is “well founded” before proceeding. One of the arbitrators in the Philippines case, speaking in an earlier case, likened this to the standard “beyond reasonable doubt” applied in criminal cases in common law countries – which is of course an exacting standard. The question here is ultimately whether the Tribunal applied this high standard in deciding that it had jurisdiction to hear the Philippines' claims.