Colonialism is the establishment and maintenance, for an extended time, of rule over a people that is separate from and subordinate to the ruling power. It imposes alien, authoritarian and more or less repressive regimes on materially inferior societies. Colonialism, because it moulds geographically, culturally, politically, socially and economically the life of subordinate societies to meet the needs of the colonial powers, not only violates, in the present, the elementary rights to self-determination but jeopardizes future possibilities of self-centred development.
When the international community became aware of the seriousness and extent of the calamity of slavery, it undertook to abolish it but had already opened the door to another form of exploitation and domination: colonization. The slaving Powers turned into colonial Powers. As in the previous system, the conflicts that preceded and accompanied colonial conquests were brutal and inhuman. Professor Mohamed Bedjaoui has defined colonization as a social, economic and political act. It expressed itself, he says, in the legal relationships of domination and exploitation. From the point of view of international law, it is nothing else but an attempt to establish a relationship of subordination between two nations in every sphere.
Colonization entailed the destruction and modification of the structures of the colonized peoples. The models of civilization and development imposed on them served only to deepen and worsen the work of destruction undertaken by the colonizers, who were not interested in helping the colonized peoples to escape from their ignorance. The international community, through its deliberative body of the period – the General Assembly of the League of Nations – which was dominated by the Western countries, had authorized those countries to divide up the third world and form colonial empires. They then had the backing of the international community to plunder the third world and to dispossess the colonized peoples of almost all their lands and possessions. Thus encouraged, they stopped at no form of exploitation, taking advantage to develop their own countries and to enrich their peoples.
Slavery and colonization ended up by ruining the entire third world which, moreover, has never recovered. For centuries, the colonial Powers, which are easily identifiable today, pillaged the wealth of the colonized countries to the profit of and on behalf of their nationals and to ensure their own economic and social development. The colonized peoples and countries, worn out and ruined as they were, finally took up arms to free themselves at the cost of enormous sacrifices. It is now neo-colonization that is perpetuating the domination and exploitation of the countries caught up in the machinery of the system.
The decolonization movement, after the severing of the bonds of domination and exploitation, posed the problem of the relationships between the former colonies and the colonizer in terms of development, equality and restitution of wealth which, of course, encountered the resistance of the debtor countries. This gave rise to the saying that one of the prerequisites for decolonization was to secure the previously existing status quo.
One of the most important factors in maintaining that situation is the cooperation provided by the former colonial Powers, which uses a series of constraints to impose its will on the former colony, now a "sovereign State" but actually without means or power. In this unequal relationship between assisted and assister, the latter imposes its will and thus maintains the general orientation of existing or new structures in the economic, social and cultural spheres. Whatever form decolonization took, whether violent or negotiated, it has led everywhere to the same disastrous result of dependence and exploitation, maintaining an unjust world economic order which the developing countries, composed essentially of former colonies, insist should be revised to achieve a fairer balance.
Colonialism as described above, no longer occurs; the last colonial empire (Portugal) collapsed in 1975. If the term is still widely used, it is to denote (abusively) situations similar in some but not all aspects to colonial domination (apartheid, neo-colonialism) or that have risen with the process of decolonization (Commonwealth nations, dependent territories, associated States, dependencies, condominiums, UN Trust Territories, territories, unincorporated territories, overseas territories, overseas departments, self-governing territories, self-governing associations). Often colonial situations have been endorsed by the international community with the consequence that, although colonies as such have disappeared, the peoples have become minorities: more or less integrated, more or less discriminated against (Sahahuris, Basques, American Indians, Sikhs, Armenians, etc.).
Many of the events that have shaped Africa's geo-political, socio-economic and environmental development over the past century are related to the colonization of the region and its subsequent partition in 1885 among several European countries. During the first half of the 20th century, the colonial authorities imported economic development policies and patterns which largely neglected the adverse impacts on the poor majority of people and on the environment. On achieving independence during and after the 1960s, African governments inherited and maintained centralized economic and sectoral institutions and narrowly focused economic growth policies, usually with the encouragement and support of international aid agencies. These national and international 'development' policies, in combination with rapid population growth and increased poverty, had progressively adverse impacts on the state of the environment throughout the continent.