Why do you have international laws?

International laws are meant to regulate relations bewtween countries and judge whether deeds between relating countries are right or wrong. Those deeds allowed by the linternational laws are considered right whereas not allowed are wrong. For example, A.B.C. weapons are forbidden by a international law. If one country is a party member of the law, the country has the obligation not to use these weapons otherwise the country is against the law. Another example, if country A has agreement with country B that both countries agree that their citizens are free to travel within the two countries without visa, neither of the two countries has right to refuse any citizen from country A to enter country B. International laws must be made by independent countries or international organizations.