判例に基づき、日本及び韓国の主張する竹島の実効支配が、国際法に基づく権原（法的根拠）になるのか検証してみる。

日本の実効支配の検証

常設仲裁裁判所　Eritrea-Yemen Arbitrationの判例を参考にして検証
http://www.pca-cpa.org/ENGLISH/RPC/EY/ch7ER-YE.htm

Fishing Activities by Private Persons
For state activity capable of establishing a claim for sovereignty, the Tribunal must look to the state licensing and enforcement activities concerning fishing described above.
主権行使を立証する国家の活動として、裁判所は漁業許可及び漁業に関連する執行活動に着目しなければならない。

＜該当する日本の実効支配の証拠＞

Activities on the Islands
In order to examine the performance of jurisdictional acts on the Islands, the Tribunal must consider evidence of activities on the land territory of the Islands as well as acts in the water surrounding the Islands. This evidence includes: landing parties on the Islands; the establishment of military posts on the Islands; the construction and maintenance of facilities on the Islands; the licensing of activities on the land of the Islands; the exercise of criminal or civil jurisdiction in respect of happenings on the Islands; the construction or maintenance of lighthouses; the granting of oil concessions; and limited life and settlement on the Islands.
周辺海域と同様に、島での管轄権に関する行動の証拠を検証しなければならない。例：上陸記録、施設の建設・維持管理等。

＜該当する日本の実効支配の証拠＞

韓国の主張する実効支配の検証

国際司法裁判所　 Ligitan and Pulau Sipadan 島の判例を参考にして検証
http://www.icj-cij.org/icjwww/idocket/iinma/iinmajudgment/iinma_ijudgment_20021217.PDF

＜主張１：現在、韓国は竹島を実効支配している＞
The Court further states that "at the time when these activities werecarried out, neither Indonesia nor its predecessor, the Netherlands, ever expressed its disagreement or protest".

他国による不同意や講義の表明がある実効支配は権原（法的根拠）とならない。日本が抗議しており、現在の韓国の占有は無効。


＜主張２：安龍福が江戸時代に竹島は韓国領と宣言した＞
Finally, Indonesia states that the waters around Ligitan and Sipadan have traditionally been used by Indonesian fishermen. The Court observes, however, that activities by private persons cannot be seen as effectivités if they do not take place on the basis of official regulations or under governmental authority.

個人の活動は実効支配とみなされない。安龍福は「個人」であり、実効支配の証拠にならない。

＜主張３：1899年勅令41号で宣言した＞
The Court finally observes that it can only consider those acts as constituting a relevant display of authority which leave no doubt as to their specific reference to the islands in dispute as such. Regulations or administrative acts of a general nature can therefore be taken as effectivite's ・・・

疑いのない明確な表示が必要。勅令の「石島」は、どこの島か不明。