HMS Defender
HMS Defender © Crown Copyright

Dr David Turns, Senior Lecturer in International Law in the Centre for Defence Management and Leadership at Cranfield University, comments on international legal issues in connection with the recent incident involving HMS Defender off the coast of the Crimea peninsula:

"Although the UK Government has professed surprise at the speed and severity of Russia's reaction, some sort of confrontation was surely predictable once it became known that the destroyer HMS Defender was being detached from the Royal Navy's Carrier Strike Group in the Mediterranean Sea in order to conduct "its own set of missions" (of unspecified nature) in the Black Sea. The 'HMS Defender Incident' occurred on 23 June 2021 approximately 9 km off Cape Fiolent in Crimea, and may or may not have involved live warning fire and bombs being directed at the British warship by Russian air and sea forces, depending on whether one believes the British or Russian official accounts. While misinformation and mutual denials are only to be expected in such circumstances, they make the international legal aspects and their potential implications for UK defence and security more difficult to evaluate than was already the case.

"The two nations' narratives differ not only on the facts, but also as to the applicable legal framework; the only point they have in common was that Defender was briefly present, without prior authorisation of the littoral State, within the territorial waters off Crimea. The Secretary of State for Defence, in his statement to Parliament on 24 June, concentrated on Defender's right of innocent passage under international maritime law. Briefly put, this allows ships of all States to pass freely and without prior authorisation through another State's territorial sea in order to travel in a "continuous and expeditious" manner from one point to another. Defender was en route from Odessa to Batumi: a quick glance at a map of the Black Sea region clearly shows that such a route could reasonably be expected to pass by the vicinity of the south-western coast of Crimea. The 1982 United Nations Convention on the Law of the Sea (UNCLOS) does not explicitly specify that warships benefit from the right of innocent passage without prior notification or authorisation, although it might reasonably be inferred that they do from other treaty provisions, and a 1989 USA-USSR Joint Statement averred that such is the case.

"The Russian MoD's statement, on the other hand, although it does briefly describe Defender's action as "a blatant violation" of UNCLOS, laid much greater emphasis on the allegation that the ship's presence within the 12 km territorial sea was a violation of the national border. Article 19 of UNCLOS does specify that passage is not considered innocent if it is "prejudicial to the peace, good order or security of the coastal State", one of the indicia of which is if a ship engages in "any act of propaganda aimed at affecting the defence or security of the coastal State", and this may have been what the Russians were getting at.

"At this point, the question of Crimea's political status arises. Which is the "coastal State" whose defence or security might have been affected? Crimea has been under Russian effective control since 2014, a situation which international law considers to be one of illegal occupation; certainly, the UK "does not recognise any Russian claim to these waters", and Defender was therefore transiting "through Ukrainian territorial waters". Given this political context and what we now know about the UK MoD's intention in deploying Defender to the Black Sea, in particular to that route between Odessa and Batumi, with its proximity to the major Russian naval base at Sevastopol, it would not have been unreasonable to expect a harsh Russian reaction which resorted to (in the Russian account) threats of force.

"Those threats have since been repeated by the Russian Deputy Foreign Defence Minister and point to perhaps the real lesson of this incident: the risk of unintended escalation. Rules of Engagement (ROE) exist in part to prevent this sort of thing happening; the problem is that we do not know what Russia's ROE are, and ignorance on this occasion seems to have prompted a certain incaution.

China will doubtless have taken good note of what happened off Cape Fiolent; what will the Chinese reaction be when the Carrier Strike Group reaches the South China Sea and attempts to enter similarly disputed waters that China considers to be part of its national territory?"