International Law Abstract

International law as a common language
One of the main reasons why international law is an instrument of coexistence and cooperation between States is because it provides them with a common language. States speak the language of international law. States (and peoples within States) may have very different and diverging political discourses, cultural references, economic priorities and spiritual understandings of life -- however, one if not the only normative language that brings them together is international law. States will always try to justify their actions in light of international law. Maybe those justifications will not be correct and their actions will be in breach of international law -- either because the facts do not match the law they invoke, or because their interpretation, understanding, of the law is wrong. But no State ever says publicly: "I very well know that what I am doing is in contradiction with international law, but I could not care less".
Of course, any State would use a more diplomatic language to say that. However, States never say things like that in substance and in public. They will always try to give reasons for their actions, and reasons that make sense under international law. One thing is to say that you consider what you do to be politically good and desirable (but that is obvious and the other States will respond they simply are of a different view); another thing is to say that, additionally, it is legitimate under international law. From that moment onwards, the other States will be able to react and respond to the legal argument presented in support of the action they oppose (or agree with). International law will serve as a mediating language, a professional language of justification, and political intentions and goals will need to be phrased, using the language of international law. In that sense, (international) law domesticates politics.