Some history of how all this came about. During the Middle Ages freedom of navigation on the High Seas was curtailed by maritime powers that asserted territorial sovereignty over various bodies of water. Challenges by other countries to such claims increased markedly during the 16th. and 17th. Century's CE largely because of the growth in world trade following discovery, exploration and colonization of new lands by European powers.
The legal basis for claims of territorial sovereignty over the 'High Seas' was dealt a severe blow by the Dutch jurist Hugo Grotius who is regarded as the 'father' of International Law. Grotius on the basis of Roman legal principle contended in his Mare Liberum (Free Sea) 1609 CE that the seas could not constitute property because they cannot be occupied in the sense in which land can be occupied. Therefore they are free to all nations and subject to none. In the 18th. Century CE the Dutch jurist Cornelius van Bynkershoek formulated the important principle of international law that the waters adjoining the shores of a country within the range of artillery on land are not included in the judicial meaning of the term 'High Seas'. These waters are under the territorial sovereignty of the contiguous country. This principle was subsequently adopted throughout the world. A distance of three (3) nautical miles, 5.556 km was generally accepted but this limit was challenged in the 20th. Century CE and many countries claimed six (6) nautical miles, 11.112 km and some claimed twelve (12) nautical miles, 22.224 km.
In the late 18th. Century CE several attempts to curtail free navigation on the High Seas were made by powers such as the United Kingdom. They sought in time of war to stop all trade of other nations with its enemies, these were the Navigation Acts. A notable example of the assumption of such rights was the blockade of western European ports during the Napoleonic Wars. The United States replied with the Embargo Act (1807 CE) and the Nonintercourse Act (1809 CE). Another instance was the molestation by the English of United States shipping on the High Seas. This in turn was one of the direct causes of the War of 1812 CE.
Controversy over conflicting rights of neutrals and belligerents occupied a prominent place in international affairs throughout the 19th. Century CE and the first decade of the 20th. Century CE. The Declaration of Paris of 1856 signed during the Crimean War by the United Kingdom and France, later accepted by most other powers, increased freedom of the seas for neutrals. The Declaration of London of 1909 resulted from an international naval conference convened to resolve certian questions regarding trade and contraband raised at the second Hague Conference. Although the Declaration further defined neutral rights it was never ratified.