The choice of a treaty: Interaction between hard law and soft law in United Nations law-making

From a lawmaking perspective “soft law” is simply a convenient description for a variety of non-binding normatively worded instruments used in contemporary international relations by states and international organizations. Examples include UN conference declarations, appropriately worded resolutions and declarations adopted by the UN General Assembly or one of its subsidiary organs or specialized agencies, or codes of conduct, guidelines, and principles adopted by any of these UN organs. The main advantage of adopting rules and principles in soft-law form is that the process is simpler, faster, and potentially more inclusive than a multilateral treaty. The UN has pioneered the use of soft law, most obviously through the adoption of General Assembly resolutions that, inter alia, interpret and amplify the UN Charter, codify and progressively develop international law, provide evidence of opinio juris on new norms and general principles, or legitimize state practice. The functions of soft law in the international legal system—and in UN practice—are diverse, but it would be wrong to see the choice of instrument—treaty or soft law—in either/or terms. Non-binding soft law sometimes presents alternatives to lawmaking by treaty; at other times it complements and amplifies treaties while also providing different ways of understanding the legal effect of different kinds of treaties. But it is inconceivable that modern treaty regimes or international organizations such as the UN could function successfully without resort to soft law.