Extraterritorial Application

Consider the following scenario: the United Kingdom, together with the United States and other allies, invaded Iraq in 2003. From that point on, there was an international armed conflict between the UK and Iraq. Further, as it obtained effective control over certain parts of Iraqi territory, the UK became the occupying power of these territories. Under Art. 21 of the Third Geneva Convention, and Arts. 41-43 of the Fourth Geneva Convention, the UK had legal authority to subject enemy POWs and civilians to internment. Yet, on the other hand, the UK is a state party to the European Convention on Human Rights. In some circumstances, the ECHR applies extraterritorially. What those circumstances are is an (overly) complex question, but the UK has conceded in the Al-Skeini case before its domestic courts that the ECHR applies to extraterritorial detention. Unlike Article 9 ICCPR, which sets a standard by prohibiting arbitrary arrest and detention, Article 5 ECHR contains a categorical prohibition of detention, except on a limited number of grounds. Preventive detention or internment on security grounds is not one…