5月10日，美国军舰第三次非法进入中国南沙群岛有关岛礁邻近海域。尽管事实上美国的“航行自由计划”已实施多年，且并非单独针对中国，但是，我们仍需要根据1982年《联合国海洋法公约》（以下称《公约》）审视美国“航行自由计划”的合法性，以了解其在建立以美国为主导的世界海洋法律秩序以及在实施“重返亚洲”战略中的作用和反映出来的真正意图。

为全面分析“航行自由计划”行动的合法性，有必要回顾一下该计划的历史背景。在《公约》通过之前，“航行自由计划”于1979年在卡特政府时期正式推出。根据美国国防部的情况介绍，“航行自由计划”旨在保护美国的国家利益，反对有关沿海国的过度海洋主张。美国的“航行自由计划”行动既包括外交沟通，也包括军事宣示。按照美国的说法，该计划对同盟的、友好的、中立的以及不友好的过度声索国一视同仁。事实上当然不会如此。

尽管美国声称是为了“根据国际法捍卫所有国家的权利和自由”，但“航行自由计划”行动的合法性在以下几个方面仍然存在严重问题。首先，“航行自由计划”违反了国际法关于和平解决争端的基本原则。《联合国宪章》第2条第三款以及《公约》第279条均规定所有国际争端都应通过和平方式解决。对于《公约》的解释和适用问题，各国持不同见解是一种正常情况。大多数国家会通过谈判、斡旋、磋商等和平方式解决争端，而美国是唯一一个无视自身国际义务、习惯性选择军事力量强行执法的国家。

其次，这种对抗性强的“航行自由计划”构成“滥用权利”的行为，既违反了《公约》第300条的规定，也违反了“滥用权利”作为国际法渊源的一般原则。航行自由并不代表毫无限制的绝对自由。根据公约，世界海洋划分为不同的管辖区域，不同区域适用不同的航行制度，比如适用于领海的无害通过制度、适用于国际航行海峡的过境通行制度、适用于群岛水域的群岛海道通过制度等等，这些航行制度下的权利和义务内容各不相同。基于美国自己而非国际社会公认的对这些航行制度的理解，美国在执行“航行自由计划”行动时经常无视其国际义务，滥用航行权利。

更为明显的是，美国“航行自由计划”行动违反了“和平目的”或者“和平利用”海洋的原则，该原则在公约序言、公约第301条以及有关海洋多种用途的诸多条款中均有提及。当美国军用舰机航行数千英里出现在沿海国家门口的领海附近以及专属经济海域，夜以继日地进行收集情报和炫耀武力时，很难让人认为此类威胁性行为是出于和平目的。就此而言，“航行自由计划”行动是对沿海国家主权安全的公然威胁。视情况的严重性而定，“航行自由计划”行动可能会同时违反《联合国宪章》第2条第四款关于禁止在国际关系中威胁或使用武力的基本原则。

从沿海国管辖权的角度来看，“航行自由计划”行动还违反了适用于不同管辖海域的沿海国国内法。以饱受争议的军舰行驶无害通过权为例，美国一贯主张，军舰同商船一样享有无害通过权是国际公认的一般国际法。事实上，这种典型的美国强权看法只为少数海洋强国支持，并没有获得国际社会的普遍认可。根据联合国法律事务厅海洋事务与海洋法司提供的数据库，至少有52个国家颁布的国内立法限制军舰无害通过权，方式包括要求预先通报、许可、批准或授权。这52个国家的数据本身就足以说明问题。行使无害通过权的“航行自由计划”行动明显违反了沿海国的国内法，这种违法行为不能仅仅因为美国自己对《公约》有不同理解而得到宽容。

美国“航行自由计划”行动也违反了《公约》多处提及的“适当顾及”的义务。特别是，公约在序言中强调“适当顾及所有国家的主权”，公约第68条要求在专属经济区内活动的海域使用国“适当顾及沿海国的权利和义务”。对于在专属经济区内开展的“航行自由计划”行动，执行任务的军用舰机应适当顾及沿海国的权利与义务，并遵守沿海国的法律法规，尤其是有关海洋科学研究以及海洋环境保护方面的法律。事实上，为保护美国专属经济区内的海洋哺乳动物免受先进的军事声纳设备的影响，美军的很多军事活动在其本国专属经济区内遭到禁止。美国将此类破坏环境的军事活动转移到其他沿海国家的专属经济区，这的确是一件很不光彩的事情。

有人可能会提出质疑，既然美国并非《公约》当事国，就不能以《公约》为标准来评价美国的“航行自由计划”行动。这一问题的答案可以在美国对《公约》的态度中轻而易举地找到。美国一直认为《公约》关于航行和飞越权的规定反映了国际习惯法。考虑到《公约》作为“一揽子”协议的性质，任何国家都不能只选择适用那些对自己有利的条款，认为其反映了国际习惯法，而摒弃那些对自身不利的条款，认为其没有反映国际习惯法。考虑到《公约》当事国的庞大数量以及统一的国家实践，可以说上文提及的许多国际义务已成为国际习惯法，因而对包括美国在内的非当事国同样具有约束力。

表面上看，美国的“航行自由计划”行动是为了满足其对世界海洋的私欲，它的唯一目的在于为其海空军部队提供最大的灵活性和机动性。实质上，通过强制执行美国眼中的国际法而无视国际公认的国际法，这类明显具有挑衅性质的行动表明美国意欲实施霸权扩张，从而建立一个凌驾于以《公约》为保证的世界海洋法律秩序之上的由美国主导的海洋法律秩序。而具体到美国在中国南海执行的“航行自由计划”行动，只不过是美国实施“重返亚洲”战略的工具而已。

On May 10, the US warship illegally entered waters near the controversial reefs of China's islands in the South China Sea for the third time. It is true that the US Freedom of Navigation (FON) Program has been in place for many years, and it does not purport to target China alone. However, the lawfulness of the FON operations warrant examination in light of the 1982 International Law of the Sea Convention so as to know the role and intent of the FON Program in building a US-dominated world oceans legal order and in carrying out the “Pivot to Asia” policy.

A full analysis of the lawfulness of the FON operations necessitates a look back upon the program's historical background. It was formally instituted during the Carter administration in 1979 before the adoption of the convention. According to a fact sheet of the US Department of Defense, the FON program aims to preserve American national interest and demonstrate a non-acquiescence to excessive maritime claims asserted by coastal states. It includes both diplomatic communications and operational assertions. The US asserts that the Program impartially targets excessive claims of allied, friendly, neutral, and unfriendly states alike.

Despite the US claim “to uphold rights and freedoms of all states under international law”, the legality of the US FON operations can be challenged on several fronts. First and foremost, the program violated the general principle of international law to settle disputes peacefully. This principle is enshrined in both Article 2(3) of the UN Charter and Article 279 of the convention, both of which mandate that all international disputes are to be settled in a peaceful manner. It is not uncommon that states have different understandings with regard to interpretation and application of the convention. While most states choose to settle their disputes through peaceful means of negotiation, mediation and consultation, the US is the only country that habitually enforce its own will with warships and military aircrafts with blithe disregard for its international obligations.

Then, the confrontational FON program constitutes an “abuse of right” contrary to both Article 300 of UNCLOS and more generally under general principles of international law. The freedom of navigation does not mean absolute freedom without any restriction. Under the convention, the world's oceans are divided into various jurisdictional zones where different navigational regimes apply, such as innocent passage applied in territorial seas, transit passage applied in straits used for international navigation, archipelagic sea lanes passage applied in archipelagic waters, etc. The freedom of navigation comprises those various navigational regimes, the rights and obligations of which are quite different. Based on its own understanding of the terms of those regimes instead of those shared by international community, the US operations have often abused those navigational rights in defiance of international obligations.

For more apparent reasons, the US FON operations violated the principle of “peaceful purpose” or “peaceful uses” of the seas and oceans, which is stipulated in the Preamble，Article 301 and as well many provisions of the convention in relation to the various uses of seas. When advanced US warships and aircrafts travel across thousands of miles to the threshold of the territorial seas and EEZs of coastal states to conduct daily intelligence gathering activities and routine show of force, it is hard for anyone to take those threatening behaviors as being for peaceful purposes. The FON operations in this regard constitute a flagrant threat to coastal states' sovereignty and security. Depending on the seriousness of cases at issue, the US FON operations could simultaneously violate the fundamental principle of prohibition against the threat or use of force in international relations as embodied in Article 2(4) of UN Charter.

From the perspective of jurisdiction of coastal states, the FON operations also violated coastal states' national laws applied in various jurisdictional zones. Take the most controversial issue of exercise of innocent passage by warships for instance, while the US has always argued that the right of warships to innocent passage is generally recognized international law, it is typically American perspective shared by only a small group of major maritime powers in stead of by the international community as a whole. Based on the database provided by the Division for Ocean Affairs and the Law of the Sea of the UN Office of Legal Affairs, there are altogether at least 52 states that enact laws putting restrictions on the exercise of the right of innocent passage by warships, including prior notice, permission, approval or authorization. This figure of 52 states does speak for itself. The violation of coastal states' national laws with regard to innocent passage by FON operations cannot be tolerated by virtue of America's own understanding of the convention.

The FON operations are also inconsistent with the “due regard” obligation under the Preamble of the convention, which emphasizes “due regard for the sovereignty of all States”, and as well under Article 68, which requires the user states in the EEZ to have “due regard to the rights and duties of the coastal State”. For FON operations conducted in the EEZs, the warships and aircrafts shall have due regard to the rights and duties of the coastal State and shall comply with the laws and regulations adopted by the coastal State, in particular with regard to MSRs and marine environment protection. In fact, many of the US military activities have been prohibited in the US EEZ so as to protect the marine mammals from harms done by advanced military sonars. It is disgraceful to move those environmentally harmful military activities to the EEZs of other coastal states.

One may argue that UNCLOS could not be applied to judge the US FON operations since the US is not a party to the convention. The answer to this question could be easily found in the American stance with the convention, which has longed viewed the navigational and overflight rights it contains as reflecting customary international law. One cannot only pick up those articles of the convention to one's advantage as reflecting customary law and disregard inconvenient articles as not reflecting customary law. In terms of the high number of state parties to the convention and uniform state practice in this regard, the aforementioned obligations can be said to have become customary international law so as to also bind non-party states like the US.

On its face, the US FON program is an effort to assert US desires upon the world oceans for the sole purpose of affording its naval and air forces the maximum degree of mobility and flexibility. In essence, through enforcing American perspective of international law in defiance of shared international perspectives of international law, the apparent provocative nature of such assertions exposes the FON operations as exercises of hegemonic power projection so as to establish a US-dominated maritime legal order beyond a world ocean legal order guaranteed under the convention. As for the FON operations conducted in the South China Sea, they are no more than a tool to carry out the US “Pivot to Asia” strategy.