Even though the labelling of the international system after 1991 as unipolar is occasionally contested depending on the varying definitions of unipolarity, the ‘dissolution’ of the Soviet Union in December 1991 can be seen as the conversion into international law of the transformation of the international system from a state of bipolarity to a state of unipolarity due to the loss of one of the two poles. On the one hand, the influence of the United States on the development of international law – as hegemonic power in this unipolar system – has generated special interest. On the other hand, the increased importance of the ‘international community’, accompanied by a decreasing significance of power and the ability to use force, raises severe doubts with regard to the ability of a hegemonic power's ability to shape the legal regulation of the use of force.

The so-called doctrines of the 1990s

The label ‘doctrine’ has been used for several declarations of principles between 1991 and 2000, making the use of the denomination ‘doctrine’ during this period of time almost inflationary. Yet it is questionable to what extent these declarations constitute doctrines of US security policy in terms of the definition on which this work is based. They may constitute declarations of another kind, such as, for example, military doctrines as opposed to political doctrines.

The so-called Bush Senior Doctrine

A speech by President George Bush Senior on 5 January 1993 at the US Military Academy at West Point is generally regared as the statement of a ‘doctrine’.