導彈驅逐艦DDG106斯托克代爾號在國際海域進行常規巡航。人民解放軍（海軍）艦（舷號851）從其後方經過。（萊恩·巴切爾德/美國海軍圖片）

最近有關探尋中國與菲律賓在西菲律賓海（註：菲政府命名的南海菲律賓專屬經濟區及大陸架部分）共同開發的潛在可能性的討論，契合尋求利用政治、外交手段管理長期海上糾紛這一範式，有助於杜特爾特政府去年上台以來積極推進的實質性經濟合作。共同開發有強大的國際法特別是聯合國海洋法公約為依據，有國家實踐方面的國際先例（尤其是毗鄰南海的國家），能便捷地給各方帶來經濟好處，同時不損害主權主張，也有利於信任建設和爭端管理。然而，共同開發也常常遇到法律限制和公眾認同方面的挑戰。歸根到底，共同開發是確立有關國家的利益和求解國內外反應的一個政治操作。

過去一年裡，菲中關係出現一些積極的雙邊進展：簽訂菲中海岸警衛隊合作諒解備忘錄；建立南海問題雙邊磋商機制；東盟與中國有關南海行為準則的談判呈現出積極勢頭。

關於資源共同開發的討論清楚地表明，雙邊關係的改善如何使海上糾紛由來已久的聲索國之間的緊張態勢出現大逆轉。長久以來，對漁業和南海油氣資源的爭奪一直是糾紛的關鍵，所觸發的事件導致聲索國之間發生嚴重外交爭端，其中包括2011年的勒道（禮樂）灘事件、2012年菲中之間的斯卡伯勒淺灘（黃岩島）事件、2014年中越之間的鑽井平台事件，等等。

南海絕大部分生物和非生物資源都集中在沿岸國家的近海水域，這種資源的測繪對界定潛在的共同開發領域具有深遠影響。有趣的是，毗鄰南海的所有國家都與鄰國、包括有相同主權要求的聲索國進行了不同形式的共同開發（如1979/1990年的馬來西亞與泰國，1992年泰國與越南在泰國灣，2000年的印尼、馬來西亞和越南，2000/2005年越南與中國在東京/北部灣，2009年的汶萊和馬來西亞）。多數聲索國有共同的陸地邊界，亦或毗鄰、靠近內陸海岸（如馬來西亞和泰國、越南和中國、汶萊和馬來西亞、馬來西亞和越南）。雖然互不妥協，但一些聲索國仍與鄰國（包括與有相同主權要求的聲索國，如馬來西亞和越南，越南和中國）簽訂了專屬經濟區和大陸架劃界協議，這或許為共同開發打下更為持久的基礎。馬來西亞和越南是最積極與鄰國進行共同開發的國家，兩國恰好也是該地區最大的能源出口國（越南還是最主要的漁業產品出口國）。

與方興未艾的共同開發大環境相對應的是，菲律賓獨特的地理位置使它既沒有共享的陸地邊界，也不毗鄰或靠近內陸海岸。作為擁有幾乎是美國兩倍的巨大海域和海岸線的群島國家和海洋國家，菲律賓在海洋劃界協議方面卻是新手，經過20年艱苦談判，它在2014年才和印尼（就蘇拉威西海）簽了第一個協議。

從這個角度年看，馬尼拉對共同開發遲來的興趣，也許是因為深刻認識到它的鄰國，包括有相同主權要求的聲索國，已經長期受益於這種務實性措施，同時它們的權利主張沒有受到損害。然而，該國相對的島國特性、缺少有內陸海岸的鄰國、實際上大部分的海上油氣資源都位於西菲律賓海近海水域，所有這些，都令共同開發一直是有爭議的政治話題。與印尼（在無可爭議的內海擁有其他資源）不同而與越南（幾乎完全依靠其在南海的海上資源）相同的是，菲律賓大部分現有的以及前景看好的油氣田，都集中在西菲律賓海西部的巴拉望島周圍。

有幾個因素會影響國家謀求共同開發的決策，特別是：1）各方之間的信任和信心；2）爭議地區潛在資源的數量；3）國家領導人的形象與合法性；4）單方面開發資源的能力；5）其他國家尤其是鄰國在共同開發方面的經驗教訓。

就第一個因素而言，菲中政治關係的改善為彼此創造了更多的經濟機會，但信任赤字是否減少到足以為共同開發掃清道路，尚有待觀察。第二個因素，西巴拉望近海油氣儲量的數據至今沒有定論，雖然一些預測認為勒道（禮樂）灘的希望很大。菲律賓、越南和中國2005-2008年在這一帶的聯合前期勘探/勘探結果尚未公布，所以有關該地區潛在資源的情況依然不明。不過，假設該地區儲量可觀，共同開發也許就是大勢所趨，尤其是菲律賓方面。迄今為止，菲律賓是在南海開採離岸能源最少的國家，它也是該地區為滿足日益增長的國內能源需求最依賴外來資金的國家之一。

第三個因素，兩國領導層似乎都擁有極強的國內支持。杜特爾特和習近平都以反腐立場強硬而著稱。需要指出的是，菲律賓、越南和中國國家石油公司的三方（最初是兩方）“聯合海洋地震工作協議”並沒有發展到鑽井或生產階段，因為在國內反對派眼裡，它與當年阿羅約政府促成的與腐敗有千絲萬縷聯繫的貸款並無二致。這些貸款曾被用來在菲律賓國內實施由中國支持的基礎設施項目（如北部鐵路、全國寬帶網絡）。

關於第四個因素，中國更有能力單方開採南海的資源，而菲律賓自身能力較弱，為利用西菲律賓海當地（例如馬拉帕雅）的能源資源，不得不靠吸引殼牌、雪佛龍這樣的海外跨國巨頭作為主要參與方。但中國知道，擁有在南海從事上游業務的財力、技術和基礎設施能力，並不是它要這麼做的充分理由，因為這種單方面行動有可能引發與鄰國的外交爭端，讓它擔上以大欺小的惡名。最後，鄰國在共同開發方面的國家實踐和經驗，也許會促使雙方去做共同開發的嘗試。

實施共同開發存在多種模式，這說明，堅定的政治意願有可能激發有關各方的必要的創造力與創新，拋開法律與制度限制，擺脫媒體的煽動，找到可行的解決辦法。一些國家簽署了附帶共同開發條款的海上劃界協議（如1982年的柬埔寨和越南，1992年的馬來西亞和越南），其他國家則尋求單獨簽訂共同開發協議（如1979/1990年的馬來西亞和泰國，2000年的印尼、馬來西亞和越南）。因此，劃界並不是共同開發的障礙，也不是共同開發的必要前提條件。一些國家把共同開發當成各自能源公司之間的一個商業性生產共享協議（如2000年的印尼、馬來西亞和越南），是由一份諒解備忘錄（如1992年的馬來西亞和越南）或換文（如2009年的汶萊和馬來西亞）發展而成。一些國家還簽署了具體條約（如1974/1994年的帝汶海條約）。

菲律賓憲法為菲律賓人保留了對群島水域、領海、專屬經濟區內資源的享有權，但奇怪地遺漏了大陸（島）架。所以，從技術上說它並未禁止對該國可開採海底礦物和能源資源的大陸架進行共同開發。憲法甚至允許總統插手與外國公司的涉及技術或財政援助、以大規模勘探開發使用礦產和石油資源為目的的協議。所以，共同開發是被允許的。然而關於石油開採的現行國內立法可能形成某些挑戰，因為其所包含的具體條款，可能與共同開發相抵觸。討論適用哪一國的管轄法，一向是非常敏感的，參與方要儘力構建精心設計的合作機制，不使共同開發成為眾矢之的，避免給人一方佔便宜的感覺，雖然從性質上說共同開發不會提供這種便宜，也不會影響有爭執的主權主張。

與國與國之間的正式協議相比，一個出於商業安排的獨立的共同開發協議似乎更為可行，更容易實施，審查或許更寬鬆，國內可能的反對也會較少。雖然複雜的機制安排難度不小，需要花相當多的時間，但也可以充分挖掘現有機制中較易出成果的部分。事實上，對中國公司來說，最簡單的辦法是與本地和他國參與方合作，加入菲律賓的服務合同體系，就像當年中國國有中海油公司所做的。中海油通過（卡拉綿地區）57號服務合同進入菲律賓（購買了51%的股份），其合作夥伴是菲律賓國家石油公司（占股28%）和Mitra（占股21%）。讓這筆過去幾年蒙受政治關係惡化不利影響的交易重見天日，將是為西菲律賓海未來更多的上游業務合作鋪平道路的一個具體行動。用保全面子的解決辦法打破僵局，使一方能夠強調它的管轄，另一方能夠強調項目行為的共有性，這種安排可以在面對各自國內民眾時，讓雙方都成為贏家。

The guided-missile destroyer USS Stockdale (DDG 106) is conducting a routine patrol in international waters. A People’s Liberation Army (Navy) ship (pennant number 851) transits in the background. (U.S. Navy photo by Mass Communication Specialist 2nd Class Ryan Batchelder/ Released)

Recent talks about exploring potential for joint development between China and the Philippines (JD) in the West Philippine Sea (WPS)* fits into a pattern of finding political and diplomatic approaches to manage the longstanding maritime dispute and putting a premium on practical economic cooperation actively pursued by the Duterte government since coming into power last year. JD has considerable legal bases in international law, notably UNCLOS, enjoys international precedents for state practice (not least from states bordering the South China Sea), conveniently provides economic benefits to parties without jeopardizing claims, and contributes to confidence-building and dispute management. However, a JD is not without the usual challenges of legal restrictions and public acceptance. At the end of the day, JD remains a political exercise of defining their national interests and calculating domestic and international responses.

Philippine-China relations have seen a number of positive bilateral developments in the last year: a memorandum of understanding on Philippines-China coast guard cooperation; establishment of a bilateral consultation mechanism on the South China Sea (SCS); and positive momentum on ASEAN-China negotiations towards a Code of Conduct in the South China Sea.

Discussions of joint-development of resources clearly demonstrates the extent of how an improved climate of bilateral ties can make for a major turnaround in the relations between tight claimants over the long disputed sea. Competition for access to fisheries and hydrocarbon resources in SCS has long been a key driver of disputes and had triggered incidents that led to serious diplomatic row between and among claimants. This includes the 2011 Recto (Reed) Bank and 2012 Panatag (Scarborough) Shoal incidents between Philippines and China and the 2014 oil rig incident between Vietnam and China, among others.

Most of the living and non-living resources in SCS are clustered in near coastal waters of littoral states and such resource mapping has far reaching implications in terms of defining potential areas for joint development. Interestingly, all states bordering SCS have entered into varying forms of joint development with their neighbors, including with fellow claimants (e.g. 1979/1990 Malaysia-Thailand; 1992 Malaysia-Vietnam; 1997 Thailand-Vietnam over Gulf of Thailand; 2000 Indonesia-Malaysia-Vietnam; 2000/2005 Vietnam-China over Tonkin/Beibu Gulf; 2009 Brunei-Malaysia). Most claimants also share a contiguous land border or have adjacent or near opposing mainland coasts (e.g. Malaysia and Thailand, Vietnam and China, Brunei and Malaysia, Malaysia and Vietnam). Although mutually exclusive, several claimants have also entered into exclusive economic zone and continental shelf delimitation agreements with neighbors (including with fellow claimants e.g. Malaysia-Vietnam, Vietnam-China) which may make for a more enduring foundation for JD. Malaysia and Vietnam stand out as among the most active states in concluding JDs with neighbors and both are incidentally among the region's biggest energy exporters (in the case of Vietnam, also a major fisheries product exporter).

Set against this milieu of proliferating joint development is the Philippines with its unique geographical position of having no shared contiguous land border and no adjacent or near opposing mainland coast. As an archipelagic and maritime state with a huge maritime domain and a coastline almost twice as large as that of the U.S., the Philippines is new to maritime delimitation agreements, having signed its first one with Indonesia (over the Sulu-Sulawesi Sea) in 2014 after twenty painstaking years of negotiations.

Seen from this vantage point, Manila's late interest to enter into joint development may be motivated by this profound realization that its neighbors, including fellow claimants, have long been benefiting from this practical measure without harming their claims. However, the country's relative insularity, the absence of a neighbor with a proximate mainland opposing coast and the fact that most of its offshore oil and gas resources are located in near coastal waters in the West Philippines Sea makes joint development still a politically contentious subject. Unlike Indonesia (which have other offshore resources in uncontested internal waters) and like Vietnam (which relies almost entirely on its SCS offshore resources), most of the Philippines' existing and promising hydrocarbon fields are clustered offshore the main western island of Palawan in WPS.

There are several factors that may influence the decision of states to pursue joint development, notably: 1) trust and confidence between parties involved; 2) amount or volume of potential resources in the disputed area; 3) image and legitimacy of national leader; 4) capacity to unilaterally exploit resources and; 5) lessons and experiences from other JDs, especially from neighbors.

For the first factor, improving Philippines-China political relations are opening greater mutual economic opportunities but it remains to be seen whether the trust deficit was reduced enough to pave the way for a JD. On the second factor, data on offshore hydrocarbon deposits in near coastal waters of west Palawan remain inconclusive, although some estimates consider Recto (Reed) Bank as very promising. The findings of a joint 2005-2008 pre-exploration/exploration undertaking between Philippines, Vietnam, and China within the vicinity had not been released so knowledge on prospective resources in the area remain scarce. However, assuming there are considerable deposits in the area, momentum for a JD may surge, especially on the part of the Philippines, which so far extracts the least offshore energy from the South China Seas and is one of the region's most dependent on foreign sources in meeting its burgeoning domestic energy requirements.

On the third factor, the respective leadership of both countries seem to enjoy tremendous domestic support. Both Duterte and Xi are known for taking a tough stance against corruption. It must be noted that the tripartite (initially bipartite) Joint Marine Seismic Undertaking between the national oil companies of Philippines, Vietnam and China did not graduate to drilling or production phase because of local opposition as it was viewed as being tied to graft-ridden loans procured by the then Arroyo government to execute China-backed infrastructure projects in the country (i.e. Northrail, National Broadband Network).

On the fourth factor, China had a greater capacity to undertake unilateral resource extraction in SCS, while Philippines has a weaker homegrown capacity and had to rely on attracting major players like foreign multinational giants Shell and Chevron to harness indigenous energy resources in WPS (i.e. in Malampaya). But China realizes that having the financial, technological, and infrastructure capacity to undertake upstream activities in SCS is not enough reason for it to do so as such unilateral activities may trigger diplomatic rows with neighbors and give life to the narrative of an assertive bully. Lastly, the wealth of state practice and experience by neighbors in relation to JD may provide added encouragement for both sides to give JD a shot.

There are various modes for implementing JD demonstrating that sustained political will can imbue the needed creativity and innovativeness for parties involved to find viable workarounds from legal/institutional constraints and media sensationalism. Some states signed maritime delimitation agreements with JD clauses (e.g. 1982 Cambodia-Vietnam, 1992 Malaysia-Vietnam), while others pursued standalone JD agreements (e.g. 1979/1990 Malaysia-Thailand, 2000 Indonesia-Malaysia-Vietnam). Hence, delimitation has not been an impediment to and has not been a necessary prerequisite for a JD. Some states package it as a commercial production sharing agreement between their respective energy companies (2000 Indonesia-Malaysia-Vietnam), facilitated by a Memorandum of Understanding (e.g. 1992 Malaysia-Vietnam) or Exchange of Letters (e.g. 2009 Brunei-Malaysia). Some states also enter into specific treaties (1974/1994 Timor Sea Treaty).

The Philippine Constitution reserved the enjoyment of resources in the archipelagic waters, territorial sea and exclusive economic zone to Filipinos but curiously left out mention of the continental (insular) shelf. Hence, technically there is no expressed prohibition on joint development in the country's continental shelf where seabed minerals and energy resources are extracted from. The Constitution even allows the President to enter into agreements with foreign companies involving either technical or financial assistance for large-scale exploration, development and utilization of mineral and petroleum resources. Openings for JD are, therefore, present. However, existing domestic legislation relating to petroleum extraction may pose some challenges as they contain specific provisions which may not completely jive with JD. The discussion of whose governing law shall apply is always sensitive and participating states have come to great lengths to develop elaborate joint institutional mechanisms, if not kept the JD agreement below the radar, to avoid perceptions of giving one party some perceptual advantage, although JDs, by their nature, do not confer such advantage and do not impact on competing claims.

A standalone joint development agreement along the lines of a commercial arrangement seems more feasible, easier to implement, and may attract lesser scrutiny and possible domestic opposition than a formal grand state-to-state agreement. While sophisticated institutional arrangements may be difficult and take considerable time to come by, there are low hanging fruits well within prevailing mechanisms that can fully explored. In fact, the easiest way is for Chinese companies to partner with local and foreign players and take part in the Philippine service contract system like what China-state owned company CNOOC did in the past when it farmed-in (bought a 51% stake) in Service Contract 57 (Calamian) along with partners Philippine National Oil Company (holding 28% stake) and Mitra (21%). Reviving this deal which suffered from the adverse fallout of soured political relations in the past years is one concrete action that could pave the way for greater cooperation on future upstream activities in WPS. An arrangement that may offer a face-saving solution to break the impasse with one side able to emphasize it has governing law and the other side able to stress the project was a joint undertaking can allow both sides to come out as winners among their respective domestic publics.

*WPS is part of the South China Sea that corresponds to Philippines' Exclusive Economic Zone and Continental Shelf