“International law empowers, constrains, and compels governments in various ways and at various levels.
For example, a country that enters into free trade agreements gains economic advantages it would not otherwise enjoy but, at the same time, its freedom to pursue other policies will be affected. It may no longer be permitted to protect domestic industries, thus increasing unemployment in some sectors of the economy, and making it more difficult to promote the economic and social welfare of some of its citizens. Other parts of its economy may develop more rapidly, putting pressure on land, natural resources, water supply, and air quality, leading to unsustainable development, environmental degradation, and poorer conditions of health.
It may thus be harder to meet commitments undertaken in the International Covenant on Economic, Social and Cultural Rights or at the UN Conference on Environment and Development. Equally, those same commitments may restrict certain forms of economic development and limit the country’s ability to benefit from free trade in natural resources.
Ultimately, governments make policy choices about how to balance competing objectives of this kind on political, social, economic, or ethical grounds. These choices will be reflected in the agreements they sign or in the state practice that contributes to general international law.
The relationship between these environmental concerns, international trade policy and human rights law is best negotiated by states acting through the United Nations, the World Trade Organization (WTO), and other international organizations.
However, few governments can foresee in detail all of the consequences of the commitments they make. Even when they do foresee them, it is not always possible to secure the agreement of other governments on how to address whatever tensions may arise out of the interaction of the commitments into which they have entered.”
A. Boyle, ‘Relationship Between International Environmental Law and Other Branches of International Law’, in Bodansky, Brunnée, Hey (eds) The Oxford Handbook of International Environmental Law (OUP 2008) 126