The Tribunal found that treaties are subject to constitutional control and occupy the same hierarchical position as ordinary legislation (leis ordinrias, or “ordinary laws” in Portuguese). A recent ruling by Brazil`s Supreme Court in 2008 changed this situation somewhat by finding that treaties containing human rights provisions have a higher status than ordinary legislation, subject to the Constitution itself. In addition, the 45th Amendment to the Constitution provides for human rights treaties, approved by Congress as part of a specific procedure, the same hierarchical position as a constitutional amendment. The hierarchical position of the treaties with regard to national legislation is important for the debate on whether and how the former can cancel and vice versa. For more information on international conventions, see this article on the Harvard Law Review, the Berkeley Law Research Guide and the UCLA Law Review in this article. A treaty is a formal and binding written agreement that is concluded by actors in international law, usually sovereign states and international organizations, but may involve individuals and other actors.  A treaty can also be described as an international agreement, protocol, treaty, convention, pact or exchange of letters. Regardless of terminology, only instruments that are binding on the parties are considered treaties of international law.  A treaty is binding under international law. Articles 46-53 of the Vienna Convention on Treaty Law define the only ways to declare treaties invalid – which is considered unenforceable and void in international law.
A treaty is invalidated either because of the circumstances in which a State party has acceded to the treaty, or because of the very content of the treaty. Cancellation is separate from termination, suspension or termination (addressed above), all of which involve a change in the consent of the parties to a previously valid contract, not the nullity of that consent in the first place. 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.