AIR DEFENSE IDENTIFICATION ZONE ~ THE RESTRICTION ON THE FREE SKY DUE TO THE RESIDUAL RIGHT PRINCIPLE

防空識別區：剩餘權利原則對天空自由的限制

防空識別區是一國為國家安全目的而設置的對航空器進行識別的特殊區域，是國家行使管轄權的結果。其在國際法上的依據基於剩餘權利原則，也可以部分地基於專屬經濟區的規定，但其規範形式主要是國內法，其性質不屬於國際習慣。其法律性質不同於領空，也不等同於專屬經濟區及公海。中國設置東海防空識別區，表明了對長期以來國際社會存在的做法的認可，豐富、推動著相關國際實踐向前發展，成為國際通例乃至國際習慣。東海防空識別區與其他國家防空識別區的重疊不與現行國際法沖突。

As a result of jurisdiction exercising, Air Defense Identification Zone ( ADIZ ) is a special zone estalished by the coastal country for purposes of national sevurit in which aircraft need to be indentfied. Its legal basis in international law is the residual right principle, while its normative form is a national law, not an international custom. The Exclusive Economic Zone ( EEZ ) rules in the United Nations Convention on the Law of the Sea can partially support the establishment of ADIZ. The legal nature of ADIZ is not as a territorial airspace, and is different to the EEZ or the high seas. The establishment of the East China Sea ADIZ indicates that China recognizes the practice already exists in the international community for many years, and enhances the relevant international practice to the direction of general practice, or even an international custom. The overlapping of East China Sea ADIZ and relevant countries ADIZs is not a violation of lex lata international law.