There are several reasons why an otherwise valid and agreed treaty can be rejected as a binding international convention, most of which pose problems related to contract formation. [Citation required] For example, the Japan-Korea treaties of 1905, 1907 and 1910, which ended in series, were protested;  and they were declared “null and void” in the 1965 Treaty on Fundamental Relations between Japan and the Republic of Korea.  The end of the preamble and the beginning of the agreement itself are often referred to as “agreed as follows.” Contracts sometimes contain self-fulfilling provisions, which means that the contract is automatically terminated if certain defined conditions are met. Some contracts should only be binding temporarily by the parties and will expire at some point. Other contracts may be terminated themselves if the contract is to be concluded only under certain conditions.  Under international law, a treaty is a legally binding agreement between states (countries). A treaty can be called a convention, protocol, pact, agreement, etc. It is the content of the agreement, not its name, that makes it a treaty. Thus, the Geneva Protocol and the Biological Weapons Convention are the two treaties, although neither treaty in its name.
Under U.S. law, a treaty is a legally binding agreement between countries that requires ratification and “consultation and approval” of the Senate. All other agreements (internationally treated) are called executive agreements, but are nevertheless legally binding on the United States under international law. the Treaty on the European Union: an agreement reached in 1991 in the Dutch city of Maastricht, in which the Member States of the European Union agreed on plans for their future, including economic union and the introduction of the single currency. It came into force in 1993. UN Security Council Resolution 1540 requires all UN member states to impose effective measures against chemical, nuclear or biological weapons, their means of delivery or their related materials by non-state actors. It also includes measures to prevent the proliferation of chemical, nuclear or biological weapons. Brazil`s Federal Constitution stipulates that the power to enter into contracts is vested in the President of Brazil and that such contracts must be approved by the Brazilian Congress (Article 84, Clause VIII and Clause 49, Clause I). In practice, this has been interpreted to mean that the executive is free to negotiate and sign a treaty, but that its ratification by the President requires prior congressional approval.