Question

A a0 is a signed and approved agreement between nations.

Answer 1

A treaty is a signed and approved agreement between nations. It is an agreement reached in the environment of international law. Sovereign states, as well as international organizations, are the types of subjects that operate under international law. It can adopt other denominations such as   agreement, protocol, covenant, convention, pact, etc. Independently of the denomination used, all of them are equally considered by law and hence they are all governed by the same rules.

The functioning of treaties is similar to that of contracts. They are formed by several parties who, willingly, assume certain obligations.