Constitutional review of treaties: Lessons for comparative constitutional design and practice

Abstract

The changing remit of treaty making, such that treaties can be just as capable of negatively impacting on domestic constitutional values as ordinary legislation, results in it warranting appropriate mechanisms of domestic constitutional review. Treaties should not be exempt from what is a staple component of modern constitutionalism. There is a powerful case for constitutional systems to adopt, whether as a matter of express design or practice, both ex ante and ex post constitutional review of treaties. The concern that ex post review of treaties would threaten compliance with treaty obligations is misplaced given that it can be designed and practiced fully compatibly with international law obligations. The adoption of such a combined system of review would contribute to ensuring that treaty making does not escape the salutary reach of domestic constitutionalism, which is all the more indispensable in the absence of meaningful international law constraints on the process and substantive content of treaty making. And by ensuring greater respect for constitutional standards in the treaty-making process, including fundamental rights that are central to international law itself, this can even bolster the legitimacy of international law.