Public international law concerns relationships between sovereign nations. The sources for public international law development are custom, practice and treaties between sovereign nations, such as the Geneva Conventions. Public international law can be formed by international organisations, such as the United Nations (which was established after the failure of the League of Nations to prevent World War II),[169] the International Labour Organisation, the World Trade Organisation, or the International Monetary Fund. Public international law has a special status as law because there is no international police force, and courts (e.g. the International Court of Justice as the primary UN judicial organ) lack the capacity to penalise disobedience. The prevailing manner of enforcing international law is still essentially "self help"; that is the reaction by states to alleged breaches of international obligations by other states.[170][2][171] However, a few bodies, such as the WTO, have effective systems of binding arbitration and dispute resolution backed up by trade sanctions.[172]
Conflict of laws (or "private international law" in civil law countries) concerns which jurisdiction a legal dispute between private parties should be heard in and which jurisdiction's law should be applied. Today, businesses are increasingly capable of shifting capital and labour supply chains across borders, as well as trading with overseas businesses, making the question of which country has jurisdiction even more pressing. Increasing numbers of businesses opt for commercial arbitration under the New York Convention 1958.[173]
European Union law is the first and, so far, only example of an internationally accepted legal system other than the UN and the World Trade Organisation. Given the trend of increasing global economic integration, many regional agreements—especially the African Union—seek to follow a similar model.[174][175] In the EU, sovereign nations have gathered their authority in a system of courts and the European Parliament. These institutions are allowed the ability to enforce legal norms both against or for member states and citizens in a manner which is not possible through public international law.[176] As the European Court of Justice noted in its 1963 Van Gend en Loos decision, European Union law constitutes "a new legal order of international law" for the mutual social and economic benefit of the member states.[177][178]