ASIL Insights

One of the most basic principles of international law is freedom of maritime navigation: the freedom of one state's vessels to ply their trade on the high seas (and innocently through the waters of other states, including straits) without hindrance or interference by other states. High seas and related freedoms are now codified in the United Nations' 1982 Convention on the Law of the Sea, which is generally considered to reflect customary international law, and to which the United Kingdom and 129 other states, including Yugoslavia and Russia, are party. The 1982 Convention generally prohibits a warship from one state from visiting or boarding a foreign ship on the high seas. There are a number of exceptions, relating for instance to piracy and slavery, none of which apply here. An interception carried out in the Straits of Otranto, through which Yugoslav-bound oil must pass, appears equally difficult to justify. Ironically, it was in respect of the same general waters that in 1949 the United Kingdom brought - and won - against Albania the very first case heard by the International Court of Justice, successfully arguing that innocent passage through straits is a right recognised by international law. 

The law has not materially changed in the intervening fifty years. So a right to impose and enforce an oil blockade on the high seas or in the Straits of Otranto could be justified if based on an international treaty right - for example the United Nations Charter, or action taken by the UN Security Council under the Charter. However, the only Security Council resolution which appears remotely relevant to justify interceptions is resolution 1160, which was adopted on 31 March 1998. By that resolution the Security Council adopted a prohibition on sales of military equipment to Yugoslavia: "all States shall ... prevent the sale or supply to the Federal Republic of Yugoslavia, including Kosovo, by their nationals or from their territories or using their flag vessels and aircraft, of arms and related materiél of all types, such as weapons and ammunition, military vehicles and equipment and spare parts for the aforementioned". The resolution makes no mention of oil. It provides no basis for an oil embargo because the typical definition of "materiel" does not include oil. In the past, when the Security Council has wanted to ban oil supplies it has done so in express terms, for example in relation to Iraq. To treat oil as "materiel" here would severely undermine the prospects for future Security Council resolutions, because it would suggest that Security Council terms may be unilaterally rewritten once adopted. 

NATO's actions thus far are at least plausibly lawful, by reference to the emerging principle of "humanitarian intervention". This posits that states are not required to stand idly by as massive (and arguably genocidal) violations of human rights take place within the territory of another state. They are arguably entitled to take steps against the state perpetrating the massive violation of human rights. But even here other questions must be addressed. Why was no effort made to obtain prior authorisation of the Security Council? Why were similar measures not taken five years ago in the context of Bosnia? And why are the measures now being utilised not better designed to provide the humanitarian benefits they purport to promote, at least in the short term? If there is to be a new "Blair doctrine" justifying "humanitarian intervention" it must be based upon principles which are clearly articulated and objectively applied in the context of sound legal principles. 

A unilateral oil "blockade" enforced against third states would not be based on sound legal principles and would constitute a significant escalation. We should care whether the enforcement of such a "blockade" is or is not legal because the stability of international relations is best served by complying with the international rule of law. In the case of the law of the sea, there are additional, self-interested reasons for the most stringent and careful application of the rules. As a seafaring nation Britain benefits significantly from the rules now enshrined in the Law of the Sea Convention. They were negotiated over a period of nearly twenty years, and have achieved broad support. Amongst other matters, these rules are the backbone of Britain's international trade, its high seas fisheries activities, and its extensive programme of maritime research. The Convention's rules were also carefully designed to allow naval powers such as Britain to continue to exercise a naval presence at great distances from home. If NATO starts re-writing the rules where short-term expediency suits there is every probability that other exceptions - which are not found in the Convention - will be created and relied upon in other contexts. If NATO's actions are to continue to attract support, they must at the very least be premised upon plausible legal arguments. The imposition of an oil "blockade" against third states without their consent does not meet this standard. 

About the Author:  Philippe Sands is a practising barrister and Reader in International Law at the University of London (School of Oriental and African Studies).