Section 2: The definition of statelessness in international law 1. Definition and legal requirements of statelessness in the 1954 Convention (1) Overview As already mentioned, there is no provision that defines a stateless person in Japanese laws or regulations. However, the United Nations International Law Commission has concluded that the definition of a stateless person provided by the 1954 Convention has acquired the nature of customary law.69 Japan has not acceded to the 1954 Convention, but it is required to observe customary international law in the same way as national law based on Article 98(2) of the Japanese Constitution. Therefore, this report bases its analysis on the definition of a stateless person provided by Article 1(1) of the 1954 Convention, i.e., “a person who is not considered as a national by any State under the operation of its law.” In the case analysis in Chapter 2, whether or not a concerned individual is a stateless person is to be determined by applying the 1954 Convention definition. Regarding the criteria for interpreting the definition of a “stateless person”, in 2014 UNHCR, which has been designated as the international agency with a mandate to assist stateless persons, published the Handbook on Protection of Stateless Persons: Under the 1954 Convention Relating to the Status of Stateless Persons (hereinafter the “Handbook”).70 The Handbook was completed based on the three guidelines on statelessness released by UNHCR in 2012. While there has been some accumulation of practice and judicial decisions relating to refugee status determination, there are not enough examples of case assessments relating to statelessness determinations in the international community. Therefore, regarding the standards for interpretation of the definition of statelessness, the UNHCR Handbook, which has a mandate for the protection of stateless persons, provides the foundation. In earlier discourse relating to stateless persons, the terms “de jure stateless persons” and “de facto stateless persons” were often used, with an interpretation that “de facto stateless persons” do not fall within the scope of the 1954 Convention. However, the term “de jure stateless persons” is not used within the 1954 Convention, and the line between “de facto stateless persons” and “de jure stateless persons” is not necessarily clear. Therefore, care must be taken so that the concept of “de facto stateless persons” is 69 International Law Commission, Draft Article on Diplomatic Protection with Commentaries (2006), at http://legal.un.org/ilc/texts/instruments/english/commentaries/9_8_2006.pdf, p. 49. 70 UNHCR, Handbook on Protection of Stateless Persons: Under the 1954 Convention Relating to the Status of Stateless Persons (UNHCR, 2014), at http://www.unhcr.org/53b698ab9.html. (On the contents, see Kaneko, supra note 17d, “Commentary on UNHCR’s New Handbook and Guidelines Relating to Statelessness”.) 39