The landscape of international disputes is multifaceted: courts of general jurisdiction are flanked by special courts dealing with issues within specific areas, and investment arbitration has to a considerable extent wiped out the classical dichotomy between inter-State public international law disputes and commercial disputes.
The borders among different areas of law are increasingly getting blurred, paving the way to possible cross-fertilization within public international law.
At the same time, increased specialization may lead to parochial attitudes – developing sources and methodologies for a specific area independently of sources and methodologies of general application that could be relevant. This is part of what has been defined as fragmentation.
An area in which case law tends to concentrate on sources developed within the borders of the specific field, without necessarily seeking for inspiration in the sources generally available under public international law, is that of international administrative tribunals.
International administrative tribunals decide disputes on employment issues between an international organisation and its employees. Host country agreements, which generally form part of the constituting documents of international organisations, usually provide immunity from jurisdiction of the host county’s courts.