Denunciation is the termination of a treaty, and the result is that the treaty is no longer binding on the country that denounces it. Some countries do not require the approval of other government bodies for denunciation, leaving that decision to the full discretion of the country’s leader, such as the president. A termination clause is sometimes included in the treaty that leads to automatic denunciation. For example, some treaties terminate because the minimum number of nations is not met as a result of other countries terminating the treaty. Unlike the denunciation process, the approval of other government departments or bodies is required to adopt treaties in the first place.
Nations must often provide a notice of denunciation prior to the termination of a treaty. The amount of time varies by treaty, but six- and 12-month notices are common. The reasons for treaty termination can range from political conditions in the nation that wants to denounce the treaty to lack of funds that would enable a party to carry out its duties and responsibilities under a treaty. For example, the United States gave a notice to the Convention for the Unification of Certain Rules Relating to International Transportation by Air because it gave low limits for liability insurance for passenger deaths. The notice was later withdrawn because the convention was able to raise the insurance amounts.
Some treaties prohibit denunciation unless it can reasonably be implied that the nations intended to include that possibility. Those same treaties, however, often permit termination of the treaty in accordance with the provisions of the treaty. The Vienna Convention of the Law of Treaties states, “The termination of a treaty, its denunciation or the withdrawal of a party, may take place only as a result of the application of the provisions of the treaty or of the present Convention.” A nation that can effectively apply the provisions contained in a treaty to withdraw from it can do so despite any limits on denunciation or lack of an express provision that permits it. The nation may still be obligated to follow international law, which may overlap with some of the duties and responsibilities contained in the treaty.
Another legal test used to determine whether a nation can terminate a treaty is whether the nature of the treaty implies the right of parties to denounce it. That test originates from the convention as well. A determination is often made upon close examination of the treaty itself and the context of the treaty within international law.