CONSTITUTIONAL REVIEW OF INTERNATIONAL TREATIESBETWEEN CONSTITUTIONAL SUPREMACY AND PACTA SUNTSERVANDA: CONSTITUTIONAL RESPONSES IN CROATIA,SLOVENIA AND NORTH MACEDONIA

Abstract

This article examines the constitutional review of international treaties in Croatia,
Slovenia, and North Macedonia through the lens of the tension between constitutional
supremacy and the principle of pacta sunt servanda. While constitutional review of treaties
has received considerable scholarly attention, existing literature has focused primarily on
individual national models or broader theoretical debates concerning the relationship between
constitutional and international law. Less attention has been devoted to explaining why
constitutional systems sharing common institutional origins have developed different
approaches to treaty review. The article argues that the constitutional systems that emerged
following the dissolution of Yugoslavia provide a particularly valuable framework for
addressing this question. Although all three states inherited constitutional courts originating
within a common institutional tradition, they subsequently developed distinct constitutional
responses to the problem of reconciling constitutional authority with international obligations.
The analysis combines historical and comparative methods. It examines the historical
development of constitutional review of international treaties, outlines the principal
theoretical approaches to resolving conflicts between constitutional norms and treaty
obligations, and places the discussion within the broader context of Yugoslav constitutional
development. The article demonstrates that Slovenia has developed a model of preventive
constitutional review designed to address constitutional objections before ratification, whereas
Croatia and North Macedonia largely exclude substantive review of ratified treaties, albeit on
different constitutional grounds. While Croatian jurisprudence relies primarily on judicial
restraint motivated by concerns regarding international obligations, the Macedonian
Constitutional Court approaches the issue principally as a question of constitutional
competence. The comparison suggests that common institutional origins do not necessarily
yield uniform constitutional outcomes, and that similar constitutional institutions may produce
markedly different responses to the same constitutional dilemma.