A<u> treaty</u> 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.
It is now believed that the largest contributing factor to the decline of the Indus Valley civilization was an outbreak of disease--since there were no treatments and the density of the civilization led the disease to spread very quickly.
It started with the Chinese Exclusion Act of 1882, but 10 years later it then came to the US opening Ellis Island in which immigrates had spent time before being able to actually enter the US.
Is 3 the battle against the plague
