南海仲裁案的仲裁結果，實質上否定台灣實際佔領的南沙群島最大島嶼太平島作為“島”的性質，降格為“岩礁”，對台灣造成很大衝擊。台灣“外交部”部長李大維認為：仲裁法院針對南海的判決是先前預判中“最糟糕的情況”，其結果將台灣置於政治困境。

島內不僅對仲裁結果中稱台灣為“中國台灣當局”（Taiwan Authority of China）相當不滿，認為貶抑了台灣“主權國家地位”；也對“九段線”被裁定無效使台灣“U型線”主張受影響表示不滿。太平島不在菲律賓要求仲裁範圍內，仲裁庭卻自行擴權宣告包括太平島在內的南沙群島全部為“岩礁”，使得台灣沒有了主張太平島附近200海里專屬經濟區的權利。島內各界認為，儘管台灣既非《聯合國海洋法公約》締約方，又非仲裁參與方，完全可不接受仲裁結果，但這份裁決嚴重損害了台灣的法律地位及相關海域權利，造成深遠的實質性傷害。

民進黨當局在針對仲裁結果發表官方聲明與立場主張後，採取盡量低調的“冷處理”做法。蔡英文登艦發表演講，但並未隨艦巡航，尺度拿捏相當微妙，背後折射出蔡當局面臨來自各個面向的多重壓力：首先，前任領導人不分藍綠，皆堅持對太平島的主權。陳水扁離任前登太平島主持機場啟用典禮，宣示維護海疆與領土的完整決心。馬英九更是費勁心力，舉辦“南疆史料特展”，多次以法學專家身份“現身說法”闡明在南海U形線的一切權利，邀請國際學者及媒體記者登島，見證太平島具備《國際海洋法公約》關於“島嶼”必須具備“維持人類生存與自身經濟生活”的條件。上述前任領導人的作為都給蔡英文以壓力。

第二重壓力來自島內民眾。蔡英文在520就職典禮上宣誓依照“憲法”當選，有責任捍衛“中華民國”的“主權”和“領土”，對東海及南海問題，主張擱置爭議，共同開發。但現在一紙裁決令民眾覺得常識受到挑戰，權益受到損害。太平島周圍200海里專屬經濟區是台灣漁民的傳統漁場。仲裁結果影響台漁民原有的作業權益，增加了菲律賓、越南等鄰近國家干擾或強行扣押台灣漁船的風險。“全國漁會”對蔡當局施壓，要求其積極維護“國家”與漁民既有權益。

再者是來自美國的壓力。一直以來，美國希望台灣在南海問題上不與中國大陸聯手並保持低調，服從美國在亞太的戰略安排。仲裁事件印證了台灣作為美國一顆戰略棋子的現實。蔡英文多次表態在安全上站在美日“價值同盟”一邊，南海議題上與美保持一致，“尊重國際法及海洋公約”。但無論是馬英九力證太平島“是島非礁”，還是蔡英文的表態，都對美無實質性觸動，因美國在亞太有自身利益與戰略安排。

從蔡當局在仲裁結果公布前仍不斷提“尊重國際法及海洋法公約”，事後斷不承認仲裁決定的回應，可見其或是盲目樂觀，或是資訊不暢，亦可能是硬吞苦果。綜上所述判斷，最後一種可能性更大。此次仲裁結果在法律上將南海島礁全數判定為礁的“斬草除根”做法，不僅暴露出“價值同盟”的空洞與虛偽，也折射出美國在推動其亞太戰略時完全無視台灣的利益,全然出於美在南海域內的利益考量。

危機中也並非生機全無。蔡英文如想在“後仲裁時期”將台灣從南海困境中解套，還需正視問題根源，借鑒前人智慧，尋找真正出路。為此，蔡應改變其南海論述模糊而消極的立場。

蔡英文政府南海政策的核心問題在於：台灣的“U形線”主張包括對太平島的“主權”源於“先佔先得”的歷史性權利。但蔡政府出於“台獨”理念及現實政治，不願台在太平島權利上與中國歷史掛鉤，欲與中國大陸切割，因而片面強調《聯合國海洋法公約》，避談歷史性權利。這種矛盾的思維與避重就輕政策造成的結果，便是被其他國家利用。此次仲裁證明了蔡南海政策路徑的失敗。

南海仲裁案結果已公佈於世，但後續效應尚未全部顯現。台灣地位特殊，角色微妙，蔡英文政府儘管處於政治困境之中，但也非全無出路：第一，以清晰而積極立場制定南海政策，保護漁民利益，並效仿其前任作出主權宣誓。第二，放棄對美日所謂“價值同盟”的幻想，重新審視自身在南海問題上的角色。第三，放開心胸與眼界，看到中華民族的歷史、現況與未來，將中國歷史、台灣前途及太平島權利完全掛鉤。

The arbitral tribunal's ruling from The Hague has denied the status of Taiping Island, which has been under Taiwan's effective control, as an “island”, and reduced it into “rocks”, dealing a heavy blow to Taiwan. Taiwan “Foreign Minister” David Lee pointed out: What the arbitral panel had come up with is “the worst scenario” anticipated, which has put Taiwan in a political dilemma.

Public opinion in the island is dissatisfied not only with the ruling's addressing Taiwan as “Taiwan Authority of China”, believing it has demeaned Taiwan's “status as sovereign state”; but also with its influence on Taiwan's claims by announcing the “U-shaped line” invalid.Taiping Island is not within the scope of the Philippine-initiated arbitration. The arbitral tribunal, however, spontaneously expanded its authority and declared that the Nansha Islands, including Taiping Island, are rocks or reefs, depriving Taiwan's right to claim 200 nautical miles of exclusive economic zone for the island. There is a prevailing consensus in Taiwan that since it is neither a signatory to the UNCLOS, nor a party in the arbitration, it can completely ignore the ruling, but the decision has seriously damaged Taiwan's legal standing, and its rights in corresponding waters, resulting in lasting substantive harm.

The Democratic Progressive Party authorities, after issuing an official statement on the ruling clarifying Taiwan's official stance, have resorted to a very low-profile approach to the matter. Tsai Ing-wen boarded the military ship that was to be dispatched to Taiping Island, yet didn't join the patrol. The delicate approach revealed that the Tsai administration is under pressures from various sources. First, former leaders of the island, no matter their political camps, all asserted sovereignty over Taiping Island. Chen Shui-bien presided over the inaugural ceremony for Taiping Island's airport, demonstrating the resolve to safeguard the integrity of maritime and territorial sovereignty; Ma Ying-jeou has done everything possible in that regard: He organized an exhibition of historical materials regarding the South China Sea; on multiple occasions personally expounded Chinese rights and interests within the “U-shaped line” in the capacity of an expert in international law; and invited international scholars and media representatives to Taiping Island to prove the island is fully qualified as an “island” as the UNCLOS defines, for it satisfies the condition of having the conditions to sustain human subsistence and its own economic life. Such deeds by former leaders have all mounted pressures on Tsai.

The second layer of pressure comes from the local public. Tsai claimed in her inaugural speech on May 20 that, having been elected in accordance with the island's “constitution”, she has an obligation to safeguard the “sovereignty” and “territory” of the “Republic of China”, and stated that the East and South China Sea issues should be handled under the principle of shelving disputes and engaging in joint development. But the ruling makes people feel their common sense has been challenged, and rights and interests damaged. The 200-nautical-mile exclusive economic zone surrounding Taiping Island has been a traditional fishery for Taiwan's fishermen. The ruling has compromised the existing rights and interests of local fishermen, and increased the risk that such neighboring countries as Vietnam and the Philippines could harass or forcefully seize fishing vessels from Taiwan. The “National Fishing Association” has pressed the Tsai administration to actively safeguard current rights and interests of the “country” and its fishermen.

Then there is the pressure from the United States. The US has always hoped that Taiwan would not join hands with the mainland on the South China Sea issue, instead keep a low profile, and abide by its strategic arrangements in the Asia-Pacific. The arbitration confirmed the reality that Taiwan is a chess piece on the US' strategic chessboard. Tsai Ing-wen has vowed on multiple occasions that security-wise, Taiwan would be on the same side with the US-Japan “values alliance”, keeping pace with the US on the South China Sea issue, and “respecting international law and the UNCLOS”. Neither Ma's utmost efforts to prove Taiping Island's status as an island, nor Tsai's assurances, however, have made any difference to the US, because the latter has its own self-interests and strategic arrangements.

Judging from the Tsai authorities' constant vows to “respect international law and the UNCLOS” prior to the ruling, and from its repeated statements on not accepting the arbitration afterward, they have either been blindly optimistic, ill-informed, or grudgingly swallowing a bitter fruit. Most likely is the third possibility. That the ruling legally defined all islands and features in the South China Sea as “rocks” not only exposed the void and hypocrisy of the “values alliance”, but also demonstrated that the US is in complete disregard of Taiwan's interests while carrying out its own Asia-Pacific strategy, concentrating solely on those of its own in the South China Sea.

But that doesn't mean this is an all-crisis, no-opportunity scenario. If Tsai wants to lift Taiwan out from the South China Sea dilemma in the wake of the arbitration, Tsai needs to face the root causes of the problem, borrow wisdom from predecessors, and find a viable way out. For that, Tsai should change her ambiguous and passive stance regarding the South China Sea issue.

The central problem in the Tsai administration's South China Sea policy is that Taiwan's “U-shaped line”, including its “sovereignty” claim for Taiping Island derived from historical rights arising from “first possession”. But based on its pro-independence philosophy and current political reality, the Tsai administration is not willing to associate Taiwan's rights to Taiping Island with China's historical rights. Out of its desire to split from the mainland, it has one-sidedly emphasized the UNCLOS, while avoiding any mention of historical rights. Such self-contradictory thinking and policies have rendered Taiwan a political instrument for other countries. The arbitration has declared the failure of Tsai's South China Sea policy.

Though the ruling has been published, its impacts are yet to fully present themselves. Given Taiwan's peculiar status and its delicate role, although the Tsai administration is trapped in a political dilemma, it does have ways out: First, come up with a South China Sea policy with a clear and proactive position, protect fishermen's interests, and make sovereignty claims like her predecessors. Second, give up unrealistic expectations on the US-Japan “values alliance”, reconsider its role in the South China Sea issue. Third, with an open mind and strategic insight, look at the history, present, and future of the Chinese nation, link Chinese history up with Taiwan's future, and corresponding rights to Taiping Island.