The League of Nations and the Kellogg-Briand Pact set rules against acquisition of territory by aggression and unlawful war. However, when powerful States are not satisfied with territorial status quo and are unwilling to give up their interests for peace, there is an inherent difficulty in stopping attempts to acquire territory by force, and the legal system in the inter-war period did not succeed. The post-war efforts under the UN strengthened rules against attempts to acquire territory by force, including through the 1970 Friendly Relations Declaration adopted by the UN General Assembly (GA). Its consensus adoption indicates that Member States generally preferred to maintain territorial status quo in 1970. However, the unwillingness of States protected by veto to give up the power and the limited acceptance of the International Court of Justice (ICJ)‘s jurisdiction persist. The majority of States share a common interest in the maintenance of peace and security based on international law. GA resolutions which clearly recognise the violation of rules adopted with an overwhelming majority such as 140 in favour and less than 10 against have significant weight. The ICJ’s Advisory Opinions and, where appropriate, such resolutions may be utilised when searching for a ‘single’ standard rather than a double standard.