THE EVOLUTION OF INTERNATIONAL MIGRATION LAW

Migration has been an integral part of human activity for as long as people have inhabited the earth. Whether moving as individuals, families or tribes, migration is an age-old response to the physical need for food, shelter and security, and the psychological need for adventure and exploration. However, while migration has marked all periods of human history, the phenomenon of ‘international migration’ had to await the reordering of the geopolitical landscape as a collection of territorial States in which governments had authority over settled populations residing within defined geographic boundaries.

The Treaty of Westphalia (1648) was a critical turning point in establishing that new landscape, but for the next two centuries individuals still enjoyed substantial freedom in traversing the boundaries of the State. This reflected an attitude of hospitality to strangers that was inherited from ancient cultures and expressed through cosmopolitanism. This attitude can be seen in the scholarly works of the great writers of international law of the eighteenth and nineteenth centuries, who, with few exceptions, took a liberal attitude to the movement of people across borders for trade, commerce and other purposes. If law in this early period paid scant attention to regulating migration, it was partly for the practical reason that the number of people involved was modest because modes of transport were confined to land crossings by foot or horse, and sea crossings by wind-powered sailing vessels. There were some notable exceptions to this laissez-faire approach, but the circumstances in which law was invoked to regulate international migration were few.

Sovereignty allows States to regulate the movement of persons within and across their borders. It is a power that should not be exercised to the detriment of individual human rights. While the liberty to move freely and in a lawful manner is by no means absolute, limitations imposed by a State should be justified, necessary and proportionate to the state interest. This chapter outlines the concept of sovereignty under international law, the right of States to admit and expel persons, and the regulation and facilitation of migratory movements. By providing an overview of the international legal framework, it analyses whether any significant advancement has been made since the end of the nineteenth century, particularly on the right to leave and the right to return.

STATE SOVEREIGNTY AND CONTROL OF EXTERNAL BORDERS

The concept of sovereignty, first understood as the supreme and absolute autonomy over a particular territory, evolved from being an ‘omnipotent authority’ to a totality of legal powers and competences regulated by contemporary international law. As a concept of international law, it comprises three major aspects – external, internal and territorial – each being exercised in accordance with the rules of international law. The external aspect of sovereignty concerns the relationship between States: it is the right of a State to determine freely its relations with other States or entities without the restraint or control of another State. This aspect of sovereignty is also known as independence. The internal aspect of sovereignty is the State’s right or competence to determine the character of its own institutions, to enact laws of its own choice, and to ensure respect for and adherence to national laws. The territorial aspect of sovereignty is the authority that a State exercises over all persons and things found within its territory, as well as over its nationals abroad.

Preface

International migration has been a topic on the lips of policy makers for a very long time. The policy interests of States vary widely. Some seek to promote immigration to meet local labour shortages, or facilitate emigration to generate a stream of remittances and foster local development. Others take a more cautious approach because of concerns about irregular migration or national security, or because their societies historically have not welcomed foreigners. These different policy stances are reflected in a vast and complex array of national migration laws that span issues of nationality, entry, exit, deportation, detention, visa classes, status determination, migration-related crime and access to social services. These laws are generally well known within States because they are applied on a daily basis by immigration officials, consular officers, border patrols and crime investigators.

By contrast, the framework of international law governing migration is fragmented and unfamiliar. While some pockets are well recognised – refugee law being the principal example – many dimensions of the international legal framework remain unknown to all but a small coterie of specialists. Many individuals who formulate national migration laws, policies and practices, or are required to implement them, are thus unaware of the rich lode of international agreements, customary law, resolutions, recommendations and guidelines informing developments at the national level.