In international law, "opinio juris" is the subjective element used to judge whether the practice of a state is due to a belief that it is legally obliged to do a particular act. When opinio juris exists and is consistent with nearly all state practice, customary international law emerges. Opinio juris essentially means that states must act in compliance with the norm not merely out of convenience, habit, coincidence, or political expediency, but rather out of a sense of legal obligation. Article 38(1)(b) of the Statute of the International Court of Justice accepts "international custom" as a source of law, but only where this custom is 1) “evidence of a general practice,” (the objective component) (2) "accepted as law." (the opinio juris or subjective component) Thus, for example, while it may be observed that heads of state virtually always shake hands when they first meet, it is highly unlikely that they do so because they believe that a rule of international law requires it. On the other hand, a state would almost certainly expect some form of legal repercussions if it were to prosecute a foreign ambassador without the consent of his or her home state, and in this sense opinio juris does exist for the international law rule of diplomatic immunity.