Sir Stephen Lovegrove, the UK's National Security Adviser, says the future of the sea is under threat. Speaking at the Manama Dialogue in Bahrain, he said states have chosen to openly contest, selectively reinterpret or discreetly subvert freedom of navigation.
Law of the Sea disputes can now be heard in Singapore as it agreed to provide facilities for an international tribunal to preside over such cases in the country.
The UK has protested to Argentina over its interception of Falkland Islands-licensed fishing boats, mainly Spanish in disputed South Atlantic waters and in the River Plate when they approach the port of Montevideo.
A retired Spanish diplomat has sparked controversy after circulating a number of opinion articles that contradicted the official Spanish position on key issues including Gibraltar.