It may be asserted that freedom of navigation is the cornerstone of international intercourse. It has always been indispensable for shipping, but at the same time, in the past, it did not give rise to any significant conflict of interests. No wonder that freedom of navigation has been universally recognized as a basic norm of international law. Indeed, it is often cited as the most classic illustration of a peremptory norm of the law of nations.Freedom of navigation could not be confined to the high seas. It was soon realized that to ensure free access to and from the open sea, as well as free passage between its various parts, rights of navigation in several sea spaces other than the open sea should be recognized too. Consequently the ships of all nations are also entitled to enjoy certain rights of navigation in some areas which are subject to the sovereignty of the coastal State, particularly in international straits, even though they may form part of the territorial sea of the riparians. Whereas freedom of navigation on the high seas has long been taken for granted, these limited rights of passage have been the subject of friction and compromises between the users and the littoral State.