Defence date: 10 May 1991; Examining Board: Professor Isi Foighel, University of Copenhagen; Professor Terence C. Daintith, University of London (Supervisor); Professor Hans Jacob Bull, Nordisk Institutt for Sjørett, Oslo; Professor Francis Snyder, European University Institute, Florence; Professor Thomas W. Wälde, University of Dundee; First made available online in defence version: 16 October 2015, and withdrawn on 28 October 2015.; The online version made available in Open Access on 20 April 2016 is the shorter and reworked version as finalised in July 1991 (distributed in print by the EUI in July 1994). It is based on the original manuscript of the defence version of the PhD thesis (May 1991).