The role of the state in the modern world is a complex one. According to legal theory, each state is sovereign and equal. In reality, with the phenomenal growth in communications and consciousness, and with the constant pressure and fluidity of global rivalries, not even the most powerful of states can be entirely sovereign and independent. Interdependence and the close-knit character of contemporary international commercial and political society ensures that virtually any action of a state could well have profound repercussions upon the system as a whole and the decisions under consideration by other states. This has led to an increasing interpenetration of international law and domestic law across a number of fields, such as human rights, environmental and international investment law, where at the least the same topic is subject to regulation at both the domestic and the international levels (and indeed the regional level in the case of the European Union and others). With the rise and extension of international law, questions begin to arise paralleling the role played by the state within the international system and concerned with the relationship between the internal legal order of a particular country and the rules and principles governing the international community as a whole. Municipal law governs the domestic aspects of government and deals with issues between individuals, and between individuals and the administrative apparatus, while international law focuses primarily upon the relations between states. That is now, however, an overly simplistic assertion. There are many instances where problems can emerge and lead to difficulties between the two systems. In a case before a municipal court a rule of international law may be brought forward as a defence to a charge, as for example in R v. Jones, where the defence of seeking to prevent a greater crime (essentially of international law) was claimed with regard to the alleged offence of criminal damage (in English law), or where a vessel is being prosecuted for being in what, in domestic law, is regarded as territorial waters, but in international law would be treated as part of the high seas. Further, there are cases where the same situation comes before both national and international courts, which may refer to each other’s decisions in a complex process of interaction. For example, the failure of the United States to allow imprisoned foreign nationals access to consular assistance in violation of the Vienna Convention on Consular Relations 1963 was the subject of case-law before the International Court of Justice, the Inter-American Court of Human Rights and US courts, while there is a growing tendency for domestic courts to be used to address violations of international law.