中華民國是目前唯一對琉球主權之歸屬日本有爭議的國家。由
於中華民國與日本欠缺外交關係，因此台日雙邊分別以「日本交流
協會」和「亞東關係協會」為辦理業務，但因對琉球主權尚有爭議，
故與琉球（沖繩）地區的業務不透過「亞東關係協會」，而是由「中
琉文化經濟協會駐琉球辦事處」直接辦理。就此而言，台灣與琉球
地理上相依且有極深的歷史淵源，故對琉球主權歸屬的正確認知實
有其迫切性。
首先，琉球雖於歷史上為中國的藩屬國，但卻未曾成為中的領
土，其後日本以征服取得琉球主權，此點就當時的國際法而言並無
違法之處。中國與日本雖一度提出「分島改約」之議，但隨著日本
廢藩改縣而告罷議，中國至此不再提出異議。逮至「馬關條約」簽
署之後，更明確認定日本對琉球之主權已告確立。其次，二次大戰
前後的國際文件亦對此點無甚著墨，且中華民國在此等文件討論期
間亦無反對意見。之後，美國「託管」琉球群島，以日本對琉球保
有「剩餘主權（residual sovereignty）」為由，預留日後依主權歸還原
則（the principle of return）移轉予日本之伏筆，按理中華民國應無
法再於琉球主權歸屬議題上有所爭執。
但中華民國卻在「日華和平條約」生效後，於一九五三年八月
八日美國將琉球群島北部之奄美大島交還日本時，突然以「波茨坦
宣言」第 8 條規定日本主權限於本州、北海道、九州、四國及吾人
所決定之其他小島之內，表示其中「吾人所決定其他小島」包含琉
球群島在內，因而認為琉球群島的國際地位「應由主要盟國予以決
定」。同時，中國政府對於琉球群島並無領土要求，亦無重建其宗主
權之任何意圖；惟主張琉球居民之真實願望應受尊重，彼等必須獲
得選擇其自身前途之機會，強調此等島嶼之現狀（包括其領土之完
整）應予維持，甚至認為琉球人民應有自決權。據此，中華民國在
戰後初期突然改變對琉球群島問題的基本立場，對琉球群島的主權
歸還日本表示爭議迄今。
然而，中華民國政府對於琉球群島基本立場的改變，係違反國
際法上的「禁反言」原則，再加上若以「波茨坦宣言」第 8 條為依
據，則「舊金山（對日）和約」本即是「主要盟國的決定」，該規定
可說是已執行結束，不應再以此於琉球主權歸屬議題上力爭。至於
琉球人民行使自決權的問題方面，由於日本為民主法制國家，因此
如果琉球人民對琉球自治或獨立有所主張，隨時可提出主張或以公
民投票決定，但目前琉球人民似無此方面的要求。因此，由國際地
位與國際法面向探討，可知中華民國對琉球主權地位難以置喙，而
日本藉由「征服（conquest）」手段取得琉球領土主權，以時際法的
概念觀之亦為合法，在無其他國家反對之時，已逐漸建立其正當性。
職是之故，在台灣的中華民國不應對琉球群島主權爭議上做無謂的
爭執，而以交流發展多方合作為是。

Republic of China is the only country that holds dispute against
Japan’s possession over Ryukyu’s sovereignty. Since the peace treaty
with Japan went into effect, the United States returned Amami Island of
north Ryukyu island to Japan on August 8, 1953, where article 8 of
Potsdam Proclamation was raised, which is that Japanese sovereignty
shall be limited to the islands of Honshu, Hokkaido, Kyushu, Shikoku,
and such minor islands as we determine. Since the international status
of Ryukyu is to be determined by major allies, Ryukyu’s sovereignty then
became a disputed issue.
First of all, although Ryukyu was once a tributary state of China,
never once part of Chinese territory. Afterward, Japan obtained
sovereignty over Ryukyu by conquest. The fact did not violate the law
of the international law at the time. Though once China and Japan
signed a treaty dividing Ryukyu into two parts, such a decision was
aborted along with Japan’s abolishing tributary counties, China didn’t
propose objection ever since. After the signing of Treaty of Shimonoseki,
Japan’s sovereignty over Ryukyu was then further confirmed.
Besides, international documents before and after the World War II
didn’t have the record while Republic of China didn’t hold objection
against the move. Afterwards, the United States seized the control of
Ryukyu Islands and with the reason that Japan held residual sovereignty
of Ryukyu, the principle of return Ryukyu to Japan was reserved for the
future. In that sense the Republic of China has no position to dispute over
the issues of Ryukyu’s sovereignty.
As for Ryukyu citizen’s exercising the autonomy; since Japan is a
democratic country, if citizens of Ryukyu advocate Ryukyu autonomy or
independence, such an assertion can be proposed or a referendum can be
conducted. Yet Ryukyu citizens do not have such a request.
From the perspective of international status and law, Republic of
China has a hard call on Ryukyu’s sovereignty. Japan’s conquest of
retaining the sovereignty of the Ryukyu territory is considered legal in
terms of international law. While no other countries object such a fact,
Japan has gradually established the legitimacy. Given the situation,
Republic of China should not dispute over the sovereignty of the Ryukyu
islands, but instead bilateral exchanges and cooperation should be
promoted.