In rare cases, such as Ethiopia and the Qing Dynasty in China, local governments have been able to use treaties to at least mitigate the effects of European colonization. These included learning the intricacies of European diplomatic customs and using treaties to prevent the power from overstepping its agreement or opposing different powers. [Citation required] A contract is an official and explicit written agreement that states use to engage legally.  A treaty is an official document that expresses agreement in words; It is also the objective result of a solemn event that recognizes the parties and their defined relationships. The publication of a contract does not require academic accreditation or interdisciplinary background knowledge. In international law and international relations, a protocol is usually an international treaty or agreement that complements an earlier treaty or international agreement. A protocol may modify the previous contract or add additional provisions. The parties to the previous agreement are not required to adopt the protocol. This sometimes becomes more evident by calling it an “optional protocol,” especially if many parties to the first agreement do not support the protocol. According to the preamble to contract law, treaties are a source of international law. If an act or absence is condemned by international law, the law will not accept its international legality, even if it is authorized by domestic law.  This means that in the event of a conflict with domestic law, international law will always prevail.
 The Australian Constitution allows the executive government to enter into contracts, but it is customary for contracts to be presented in both Houses of Parliament at least 15 days before signing. Treaties are considered a source of Australian law, but sometimes require the adoption of a parliamentary act based on their nature. Contracts are managed and maintained by the Department of Foreign Affairs and Trade, which stated that the “general position under Australian law is that contracts to which Australia has joined, with the exception of those that end a state of war, are not directly and automatically included in Australian law. Signing and ratification do not allow treaties to operate on national territory. In the absence of legislation, contracts cannot impose obligations on individuals or create rights in national law. Yet international law, including contract law, is a legitimate and important influence on the development of the common law and can be used in the interpretation of laws.  Treaties can be implemented by executive measures and existing laws are often sufficient to ensure compliance with a treaty. The separation between the two is often unclear and is often politicized in disagreements within a government over a treaty, because a treaty cannot be implemented without a proper change in national legislation. When a treaty requires laws of application, a state may be late in its obligations if its legislator does not pass the necessary national laws. There are three ways to change an existing treaty. First, a formal change requires that States Parties be forced to go through the ratification process again. The renegotiation of the treaty provisions can be long and time-consuming and often some parties to the original treaty will not become parties to the amended treaty. In determining the legal obligations of states, a party to the original treaty and a party to the amended treaty, states are bound only by the conditions on which they have agreed.