Even if claims of constitutional convergence are taken at face value, however,
convergence is not comprehensive. Most obviously, internationalisation affects
some segments of constitutions to a greater extent than others. Rights protection
has converged significantly, institutional design less so. Further, internationalisa-
tion affects different states to different degrees. It has a profound impact on the
constitutional arrangements of two types of state: those in a tightly integrated supra-
national arrangement such as the European Union and developing countries in
receipt of significant international assistance or subject to sanctions of certain
kinds. Its effect on other states is much less dramatic. Finally, internationalisation
is always partial, in the sense that it never applies evenly to an entire constitutional
system, much less to the context in which it is embedded, so that an appearance of
convergence may be misleading. Even where a constitutional text is identical with
that of another state or of an international instrument it may nevertheless operate
differently for a host of reasons, including differences in the institutional arrange-
ments through which the constitution is interpreted and takes effect or differences
in values affecting priorities. Conversely, general constitutional principles on
which there is broad agreement may be understood in different ways and may
operate differently once translated into action in a particular textual and insti-
tutional framework: separation of powers and judicial independence are examples.
The distinction between constitutional form and operation is familiar in
comparative constitutional law and is considered further in the next part.
iii. forces for difference
The function of constitutions
The extent of constitutional convergence in consequence of internationalisation
cannot be assessed without taking account of some competing forces. One, which is
the subject of this section, stems from the functions that constitutions perform.
Two others, which are examined in the sections that follow, point first to the
changes in the operation of a principle, institution or legal rule when it moves
from one context to another, and second to the effects of the powerful continuing
influence of states.
A constitution is made for a particular state and, in most cases, by the institutions
and people of that state, albeit with varying degrees of international influence.
54
At the very least, a constitution prescribes in general terms the institutions through
Constitutionalism(Cambridge: Cambridge University Press, 2009 ), p. 258 ; Anne Peters,
‘Humanity as the A andΩof sovereignty’ ( 2009 ) 20 European Journal of International Law
513 , arguing that the principle of humanity is now the basis of state sovereignty.(^54) See in this volume (Chapter 3 ) Sakaguchi’s analysis of the making of the constitution of
Japan in conditions of occupation.