International (public) law that is coordinative rather than sub-ordinative as in national law. Sub-ordinative means that there is a high-low relationship between the governed (the people) and the ruling (ruler / government). The form of international law is also very broad, for example:
In terms of international law in written form
In written international law, the membership system applies. This membership can be interpreted as a formal form of involvement of one party in an agreement. Written law is the result of the Vienna Conference which stipulates that the official law applies in an agreement between countries which is implemented into an international agreement. In the international sphere, the norm that regulates specifically about international treaties is the Law of Treaty which was signed in Vienna, Austria in 1969 (Vienna Convention of 1969). This convention is the main reference in the formulation of an international agreement between countries. It regulates all aspects of international agreements including the matter of membership (party) and entry into force.
Based on the law of treaty, a member (party) is a country that has declared itself bound by an agreement, and therefore the agreement applies to that country (consent to be bound). A country that holds the status? Member? an international agreement must comply with the contents of the agreement. However, before becoming a member, the country must go through a procedure of ratification or? A statement of binding itself. Typically, the procedure for ratification or statement of binding is regulated and stipulated specifically in the relevant international treaties.
Regardless of the way of ratification, a state that is a member must comply with the contents of the agreement. However, international law still opens opportunities for a country not to carry out certain parts of an international agreement, despite its member status. The way to do this is by stating the reservation (requirements) which are generally carried out together at the time of endorsement or statement of binding.
Reservation or requirements according to the definition of Law No. 24 of 2000 concerning international treaties is a unilateral statement of a country not to accept the enactment of certain provisions in international treaties in the formulation made when signing, accepting, approving, or ratifying a multilateral international treaty. This reservation is generally proposed by a country if there is a part of an international agreement that they sign is considered burdensome. Therefore, the consequence of this reservation is the invalidation of one or more articles or parts of international agreements stated in the reservation for the member country that submitted it. For example, Indonesia declares reservation of Article 30 paragraph (1), Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment. This reservation is stated in Law No. 5 of 1998 which ratified the Convention. Furthermore, if a country does not comply with an international agreement not pre-booked, then the settlement is according to what is stated in the agreement itself. Because international treaties always include ways of resolving disputes that arise after the treaty comes into force.
In terms of international law in unwritten form
This type of law is customary international law, which is the common practice of countries in the world which is evidence of general practice that is accepted as law. International customs consist of rules of law that originate from the actions of consistent states which arise from the belief that their actions are required by law.
So what if a country does not comply with international law? Actually this is the weakness of international law. Unlike national law which has formal institutions such as legislative bodies, police officers, prosecutors, heads of government both at central and regional levels (executive) and courts that have mandatory jurisdiction to their citizens, the international legal system does not have all of them.
So, there is no legal effect arising from non-compliance with unwritten international law. But if there is a country that feels disadvantaged because other countries violate international customs, it can sue the country to the International Court of Justice.