Russia-Ukraine War at Sea: Naval Blockades, Visit and Search, and Targeting War-Sustaining Objects
On February 24, 2022, Russia’s Federal Agency for Sea and Inland Water Transport (Rosmorrechflot) announced the suspension of navigation in the Sea of Azov “until further notice” due to the commencement of “antiterrorist operations” by the Black Sea Fleet. The following day, Russia’s Department of Navigation and Oceanography issued a navigational warning that navigation was prohibited in the northwest portion of the Black Sea north of 45° 21’ “due to counterterrorist operations carried out by the Russian Navy” and that ships and vessels “in this area will be regarded as terrorist threats.”
After the Estonian-owned M/V Helt struck a free-floating mine on March 3, 2022, twenty miles south of Odessa and sank in the Black Sea, the Spanish Hydrographic Office issued two navigational warnings (0092/2022 and 0122/2022) recommending that ships avoid navigating in the northwest part of the Black Sea due to mine danger. The NATO Shipping Centre issued similar warnings , indicating that drifting mines had been detected in the western Black Sea and that the threat of more drifting mines could not be ruled out.
The Russian Federal Security Service (FSB) blamed Ukraine for the drifting mines, alleging that Ukrainian forces had deployed mines around the ports of Odessa, Ochakov, Chernomorsk, and Yuzhny and that these mines had broken loose from their moorings during a storm. Ukrainian officials denied the Russian allegations, indicating that the drifting mines were Soviet-era naval mines seized by the Russians when they invaded Crimea in 2014 and were intentionally set adrift by Russian forces to disrupt commercial shipping in the Black Sea, a violation of Hague VIII, Article 2.
On July 17, 2023, Russia’s Ministry of Foreign Affairs announced that Russia was withdrawing from the UN-brokered Black Sea Grain Initiative, which guaranteed the safe transportation by neutral shipping of grain, related foodstuffs, and fertilizer from three Ukrainian ports to global markets. As a result, Russia withdrew its safety guarantees to neutral shipping operating in the maritime humanitarian corridor and abandoned its participation in the Joint Coordination Centre in Istanbul. The Russian Defense Ministry additionally issued a warning that “from 00:00 Moscow time on 20 July, all vessels travelling to Ukrainian ports in the Black Sea will be considered potential carriers of military cargo” and that “the flag countries of such ships will be considered involved in the Ukrainian conflict on the side of Kyiv.”
Following the termination of the grain initiative, Russia initiated numerous missile and drone attacks against ship berths and grain and oil terminals in the ports of Odesa and Chornomorsk, causing damage to the ports’ infrastructure and facilities. Subsequently, after six neutral merchant ships defied Moscow’s 19 July warning and transited the Black Sea en route to the Ukrainian Danube River port of Izmail, Russian forces conducted additional drone strikes against port facilities at Izmail, damaging the cargo terminal, a grain warehouse, and a grain elevator. Russian drones previously attacked grain warehouses in the Danube-port of Reni.
Since the beginning of the war, these Russian actions and statements have been characterized as a naval blockade of Ukraine (here, here, here, here, here, here). Although the measures taken by Russia to restrict navigation in the northwestern Black Sea may have the practical effect of denying neutral ships access to Ukrainian ports, none of these activities can be reconciled with the traditional concept of a naval blockade under the law of naval warfare.
Law of Blockade
A blockade is a lawful method of warfare designed to prevent ships and aircraft of all States from entering or leaving specified coastal areas under enemy control to deny the enemy economic revenue from its exports and the benefits of imports to support its war effort (Newport Manual, §§ 7.4; 7.4.1; Commander’s Handbook, § 7.7.1; DoD Law of War Manual, §§ 13.10, 13.10.1). However, to be recognized under international law, a blockade must conform with certain criteria.
First, a blockade must be declared and notified by a belligerent State. This normally includes (1) the date when the blockade begins; (2) its geographical limits; and (3) the general scope of measures employed, to include a grace period for neutral vessels and aircraft to leave the blockaded area (1909 London Declaration, arts. 8-16; Newport Manual, § 7.4.2; Commander’s Handbook, § 7.7.2.1; DoD Law of War Manual, § 13.10.2.2). Notification is normally provided by Notice to Mariners, Notice to Airmen, diplomatic exchanges, or other official declaration or announcement by the belligerent State establishing the blockade (or the commander of the blockading force acting on behalf of the State) to all affected States (1909 London Declaration, arts. 9-10; Newport Manual, § 7.4.2; Commander’s Handbook, § 7.7.2.2; DoD Law of War Manual, §§ 13.10.2.1, 13.10.2.2). A blockade may also be authorized by the UN Security Council acting under Chapter VII of the UN Charter (art. 42) if necessary to maintain or restore international peace and security (DoD Law of War Manual, § 13.10.2.1).
An example of proper declaration and notification of a blockade was Operation Pocket Money, the U.S. mining of Haiphong and 10 other North Vietnamese harbors during the Vietnam War. President Nixon announced the establishment of the blockade on radio and television on May 8, 1972. Notification was also provided to North Vietnam and all other nations concerned, both by a letter to the President of the UN Security Council, by direct bilateral diplomatic notifications, and by Notices to Mariners. The mines were not activated for three days to allow neutral ships in the harbors to leave if they so desired.
Second, the blockade must be maintained effectively by sufficient air and/or naval forces or other lawful methods and means of warfare (e.g., naval mines) to render ingress or egress of the blockaded area dangerous (1856 Paris Declaration, art. 4; 1909 London Declaration, art. 2; Newport Manual, § 7.4.3; Commander’s Handbook, § 7.7.2.3; DoD Law of War Manual, § 13.10.2.3). Whether a blockade is effective is a question of fact (1909 London Declaration, art. 3; Newport Manual, § 7.4.3). There is no requirement that every possible avenue of approach to the blockaded area be covered and the forces necessary to ensure the blockade is maintained effectively will depend on the specific military circumstances (Commander’s Handbook, § 7.7.2.3; DoD Law of War Manual, § 13.10.2.3).
Third, the blockade must be enforced impartially against all ships and/or aircraft of all nations: allied, neutral, and enemy alike (1909 London Declaration, art. 5; Newport Manual, § 7.4.4; Commander’s Handbook, § 7.7.2.4; DoD Law of War Manual, § 13.10.2.4).
Clearly, the announcement of maritime exclusion zones in the Sea of Azov and northwestern Black Sea does not amount to a declaration and notification of a naval blockade. Even if the announcement was considered a proper declaration and notification, Russia is not able to effectively maintain a blockade of the Ukrainian coast. Having lost its strategic toehold on Snake Island, coupled with the increasing risk to naval forces by Ukrainian long-range, land-based missile batteries (e.g., sinking of the cruiser Moskva and the tugboat Spasatel Vasily Bekh), the Black Sea Fleet is no longer able to effectively monitor and control the approaches to the Danube Canal and the sea lines of communication between the Bosphorus and Ukrainian ports. Much of the Black Sea Fleet has been withdrawn to Russian naval bases in Sevastopol and Novorossiysk, outside the effective range of Ukraine’s shore-based missile systems.
Constructive blockades are not permitted under international law. The requirement of “effectiveness” prevents belligerents from establishing “paper” blockades (DoD Law of War Manual, § 13.10.2.3). Rather, a blockade is only binding if it is effectively maintained by a force sufficient to prevent access to the coast of the enemy (Paris Declaration of 1856, art. 4). This requirement corrects the abuse in the early part of the 19th century “where extensive coasts were put under blockade by proclamation,” without the presence of “any actual force, or sustained by a notoriously inadequate naval force, such as an occasional appearance of a man of war in the offing or the like.”
The ineffectiveness of the purported Russian “blockade” is illustrated by the transit of the Black Sea by six neutral cargo vessels (Ams1, Afer, Bosphorus Queen, Sahin 2, Sealock, and Yilmaz Kaptan) on July 30, 2023. These vessels sailed from Israel, Greece, and Turkey to the Ukrainian Danube River-port of Izmail, disregarding the 19 July Russian warning. All the vessels openly transmitted their destination over their Automatic Identification System (AIS). Two weeks later, on 16 August, the Hong Kong-flagged M/V Joseph Schulte, carrying 2,114 containers loaded with 30,000 tons of cargo, including food products, departed the port of Odesa en route to the Turkish Straits. The vessel’s track shows the Joseph Schulte skirting the coasts of Romania, Bulgaria, and Turkey before entering the Bosphorus Strait and the Sea of Marmara on 18 August. The vessel had been stuck in Odesa since the beginning of the war. Although the transit was hailed by Ukrainian President Volodymyr Zelenskyy as a win for freedom of navigation in the Black Sea, it is possible that Russia purposely did not interfere with the vessel because of its flag: Hong Kong China. Since the initial warning was issued on July 19, 2023, only one neutral vessel has been subject to visit and search by Russian naval forces.
Belligerent Right of Visit and Search
Visit and search is the “means by which a belligerent warship or military aircraft may determine the true character (enemy or neutral) of merchant ships encountered outside neutral waters” (Newport Manual, § 9.9; DoD Law of War Manual, § 15.3.1; Commander’s Handbook, § 7.6). Visit and search may also be exercised anywhere outside neutral waters upon all merchant vessels and aircraft (neutral or enemy) to determine the nature of their cargo, the manner of their employment, or any other facts that bear on their relation to the armed conflict (Newport Manual, § 9.9; DoD Law of War Manual, § 15.3.1; Commander’s Handbook, §§ 7.4, 7.6). Although belligerents must not, so far as possible, interfere with neutral trade or neutral freedom of navigation, the belligerent right of visit and search provides a time-honored exception to the right of freedom of the seas (Paris Declaration of 1856, art. 2; Newport Manual, § 9.9).
Given operational constraints that arise during an armed conflict, visit and search normally occurs if a belligerent suspects that a neutral merchant vessel or civil aircraft is engaged in an activity rendering them liable to capture (Newport Manual, § 9.9). A belligerent warship may undertake visit and search of a neutral vessel or aircraft if it reasonably suspects that the neutral vessel or aircraft is engaged in one of the following activities: (1) acting on behalf of the enemy or operating directly under enemy control, orders, charter, employment, or direction; (2) on a voyage especially undertaken with a view to transport individual passengers who are embodied within the armed forces of the enemy (i.e., unneutral service); (3) carrying contraband; (4) presenting irregular or fraudulent documents, lacking necessary documents, or destroying, defacing, or concealing documents; (5) breaching or attempting to breach a blockade; (6) violating regulations established by a belligerent in the immediate area of naval operations; (7) communicating information in the interest of the enemy; (8) engaging in activity rendering it a military objective; or (9) such other violations as may from time to time be recognized in law (Newport Manual, § 9.6).
A neutral merchant vessel or civil aircraft acquires enemy character and may be treated by a belligerent as a enemy merchant vessel or civil aircraft if it (inter alia) resists an attempt to establish its identity, including resisting visit and search (DoD Law of War Manual, § 15.14.2.1; Commander’s Handbook, § 7.5.2). A neutral merchant vessel or civil aircraft that acquires enemy character may be captured anywhere beyond neutral territory (Commander’s Handbook, § 8.6.2.1) and may be attacked and destroyed if it (inter alia) persistently refuses to stop upon being duly summoned to do so or actively resists visit and search or capture (DoD Law of War Manual, § 15.14.2.2; Commander’s Handbook, §§ 7.10, 8.6.2.2). Most States also agree that a neutral merchant ship acquires enemy character if: (1) it is not entitled under the domestic law of the respective State to fly its flag; (2) it is under the orders or control of an agent placed on board by the enemy government; (3) it is in the exclusive employment of the enemy government; (4) it operates directly under enemy control, orders, charter, employment, or direction; (5) it is owned by enemy nationals or enemy corporations; (6) it transfers from an enemy flag to a neutral flag, effected before or after the outbreak of hostilities, and such transfer is made to evade the consequences to which an enemy vessel is exposed; (7) it takes a direct part in the hostilities; or (8) it is exclusively engaged in the transport of enemy troops or transmits intelligence in the interest of the enemy (1909 London Declaration, arts. 46, 55-56; Newport Manual, § 3.9.2; DoD Law of War Manual, §§ 15.14.2.1, 15.15.1).
On August 13, 2023, the Russian patrol ship Vasily Bykov stopped and boarded the Palau-flagged cargo ship Sukru Okan that was en route to the Ukrainian port of Izmail. The Ukrainian Ministry of Foreign Affairs (MFA) condemned the boarding indicating that “the Russian Navy grossly violated the UN Charter, the UN Convention on the Law of the Sea, and other norms of international law.” Ukraine accused Russia of deliberately “endangering freedom of navigation and safety of commercial shipping in the Black Sea” and called on the international community to take decisive action to prevent Russia from impeding the peaceful passage of vessels through the Black Sea. The MFA emphasized that “Russia should not be able to block international routes in the Black Sea, particularly those leading to Ukrainian seaports.” An examination of Russia’s boarding of the Sukru Okan, however, demonstrates that it was a “by the book” visit and search conducted in accordance with the law of naval warfare.
After detecting the Sukru Okan off the coast of Bulgaria en route to Izmail, the Vasily Bykov hailed the cargo ship and demanded that it stop for inspection to determine if it was carrying contraband. After the master of the Sukru Okan failed to respond to the order to stop, the Russian patrol ship fired warning shots to force the vessel to heave to. Once the Sukru Okan stopped, it was boarded by Russian naval personnel. The boarding party searched the vessel and inspected the ship’s documents and passports of the Turkish crew. After it was determined that the vessel was not carrying contraband, the Sukru Okan was allowed to continue its voyage. At no time did the boarding team make threats or take adverse actions against the crew.
Targeting War-Sustaining Objects
Ukraine is one of the top agricultural producers and exporters in the world and plays a key role in supplying oilseeds and grains to the global market. Agricultural products are Ukraine’s most important exports, totaling $27.8 billion in 2021 (41 percent of the country’s $68 billion overall exports) and accounting for 10% of the world wheat market, 15% of the corn market, 13% of the barley market, and 50% of the sunflower oil market. Together, Russia and Ukraine account for 12 percent of food calories globally, including one-third of the world’s wheat and barley. Thus, the closure of Ukrainian ports at the outset of the war caused serious disruptions in global supply chains and raised fears of an international food crisis.
Following Russia’s refusal to extend the Black Sea Grain Initiative on July 17, 2023, President Zelenskyy stated that the “Black Sea grain corridor can continue to operate even without Russia’s participation.” A month later, Ukrainian naval authorities announced that temporary corridors had been established to facilitate the departure of civilian merchant ships from Ukrainian Black Sea ports. Russia responded to these announcements with missile and drone attacks against port infrastructure and facilities, including ship berths, cargo terminals, and grain warehouses.
UN officials fear that attacks on Ukrainian port facilities and grain storage facilities could have “far-reaching impacts on global food security, particularly in developing countries” and may constitute a violation of the law of armed conflict. Several members of the Security Council also criticized Russian attacks on ports and grain-storage facilities. Albania’s representative stated that the Russian attacks are disrupting the food supply chain and condemning millions (mostly in the Global South) to food insecurity. Ecuador’s representative condemned the attacks and called on Russia to end its attacks against the production and export infrastructure. The representative from Mozambique expressed concerns that the attacks on critical port facilities were a significant escalation of the war that “could lead to a full-fledged commerce war.” Japan’s representative labelled the Russian attacks as “reprehensible actions,” demonstrating a “strategy of using global food supplies as a weapon . . . .” The representative from Switzerland underscored that the Russian “attacks on port facilities . . . and the threats to civilian shipping present a dangerous potential for escalation.”
International condemnation of Russia’s attacks on port and grain facilities raises an important legal issue. Are such facilities military objectives (and thus targetable) under the law of armed conflict as a war-sustaining commodity?
During an armed conflict, only military objectives may be attacked. Military objectives are defined as “those objects which by their nature, location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage” (Additional Protocol I (AP I), art. 52(2)). While Article 52 AP I does not apply as a matter of treaty law to purely maritime engagements (art. 49(3) AP I), many States take the view that the principle it expresses reflects customary international law applicable at sea (Newport Manual, § 8.5).
Thus, the law imposes a two-part test for identifying a military objective. First, the object must make an effective contribution to enemy military action by its nature, location, purpose, or use. Second, the object’s total or partial destruction, capture, or neutralization, in the circumstances ruling at the time, must offer a definite military advantage (Newport Manual, § 8.5). States, however, disagree on “whether civilian objects that contribute to the enemy’s war-sustaining effort—as distinguished from its war-fighting effort—are legitimate military objectives” (Newport Manual, § 8.5.1.1).
For those States that subscribe to the “war-sustaining” logic, enemy export of certain goods, like crude oil, renders an oil facility or a vessel carrying such commodities a military objective because the enemy earns revenue from the sale of goods that contributes to its war-fighting effort (Newport Manual, § 8.5.1.1). During the Second World War, for example, both the United States and Japan made enemy merchant vessels military objectives subject to destruction on sight from the outset of the war. Following the attack on Pearl Harbor, the U.S. Chief of Naval Operations (CNO) issued an order to the Commander in Chief, U.S. Pacific Fleet to “Execute against Japan unrestricted air and submarine warfare.” The Chief of Naval Operations of the Imperial Japanese Navy issued a similar order on March 1, 1942, to attack enemy merchant vessels by submarines and aircraft without warning (Newport Manual, § 8.5.1.2, n. 524).
The United States is a major proponent of the “war-sustaining” position and interprets the definition of military objective to include objects that make an effective contribution to the enemy’s war-fighting or war-sustaining capabilities (DoD Law of War Manual, § 5.6.6; Commander’s Handbook, § 8.2.5). One of the first attempts to codify the law of war—the Lieber Instructions—was prepared during the American Civil War. Article 15 of the code provided (in part) that military necessity allows for the “destruction of property, and obstruction of the ways and channels of traffic, travel, or communication, and of all withholding of sustenance or means of life from the enemy . . . .” The Lieber Code influenced the further development of the law of war, including the adoption of the Hague Conventions on land warfare of 1899 and 1907. Hague IX (article 2) allows for the naval bombardment of (inter alia) workshops or plants that “could be utilized for the needs of the hostile fleet or army . . . .”
U.S. law defines the term “military objective” to include “combatants and those objects during hostilities which, by their nature, location, purpose, or use, effectively contribute to the war-fighting or war-sustaining capability of an opposing force and whose total or partial destruction, capture, or neutralization would constitute a definite military advantage to the attacker under the circumstances at the time of an attack” (10 USC § 950p(a)(1)). A similar definition is found in U.S. military manuals (DoD Law of War Manual, §§ 5.6.6, 5.6.8.5; Commander’s Handbook, §§ 5.3.1, 8.2, 8.2.5).
Examples of war-sustaining commerce include imports of raw materials used to produce armaments and “exports of products the proceeds of which are used by the belligerent to purchase arms and armaments” (DoD Law of War Manual, § 15.12.1; Commander’s Handbook, § 7.4). Similarly, “economic objects associated with military operations or with war-supporting or war-sustaining industries” have also been considered military objectives, for example, “oil refining and distribution facilities and objects associated with petroleum, oil, and lubricant products (including production, transportation, storage, and distribution facilities)” (DoD Law of War Manual, §§ 5.6.8, 5.6.8.5).
The same argument could be made for the destruction of Ukraine’s most important export—grain and other agricultural products. The resumption of grain shipments would boost the Ukrainian economy by about $20 billion in additional annual revenues. Nonetheless, despite this long-standing U.S. position on war-sustaining goods, the U.S. State Department criticized Russia’s for “weaponizing hunger and contributing to global food insecurity through its destruction of Ukraine’s civilian ports and grain infrastructure.”
Conclusion
The words we use and how we use them matter. They shape the way we perceive a particular issue. Lawyers are trained to be precise with their words. Nonetheless, it is not uncommon for the media to engage in “yellow journalism,” emphasizing sensationalism over facts to “capture the attention of a large readership and to influence public reaction to international events.” Governments can also use public opinion as a weapon to weaken an opponent’s resolve. China has perfected this strategy as one of its three warfares—strategic psychological warfare, public opinion and media warfare, and legal warfare—to influence perceptions in a way that advances its interests and diminishes the ability of its opponents to respond. Sensationalizing the conflict, however, could have the unintended consequence of empowering Russia to take more aggressive action against vessels or aircraft, neutral or enemy, that breach or attempt to breach the purported “blockade.”
If a blockade line has not been declared, determining if there is a breach or attempted breach of blockade will be a question of fact for the enforcing commander. A vessel that departs from a blockaded port or a vessel that sails toward the blockaded area with the intention breaching the blockade will normally constitute an attempted breach of blockade. Moreover, under the “doctrine of continuous voyage,” Russia could take the position that “it is immaterial [whether] the vessel or aircraft is, at the time of interception, bound for neutral territory if its ultimate destination is the blockaded area.” Any vessel or aircraft breaching or attempting to breach a blockade is liable to capture and condemnation or diversion. Moreover, if a vessel or aircraft resists capture or diversion, is may be liable to attack (Newport Manual, § 7.4.7; DoD Law of War Manual, §§ 13.10.4, 13.10.4.1, 15.15.1; Commander’s Handbook, §§ 7.7.4, 7.10). Attempted breach of blockade is presumed if a vessel or aircraft is bound for a neutral port or airfield serving as a point of transit to the blockaded area (DoD Law of War Manual, § 13.10.4.1; Commander’s Handbook, § 7.7.4).
Ukraine’s condemnation of the boarding of the Sukru Okan is a classic example of conflating the peacetime law of the sea with the law of naval warfare. Russia’s visit and search of the cargo ship did not violate the UN Charter, the UN Convention on the Law of the Sea, or any other norms of international law. As a belligerent in an international armed conflict, Russia has the right to conduct visit and search of neutral vessels outside neutral waters to determine the nature of their cargo, the manner of their employment, or any other facts that bear on their relation to the armed conflict. During an armed conflict, to the extent that the peacetime regime of the law of the sea and the law of naval warfare are inconsistent, the law of naval warfare is lex specialis and prevails over the peacetime rules reflected in UNCLOS (Newport Manual, §§ 1.1, 4.1). Thus, while all ships enjoy freedom of navigation on the high seas in peacetime (UNCLOS, arts. 87, 89), the belligerent right of visit and search is a long-standing exception to this peacetime right.
Most States agree that Russia has violated its obligations under the UN Charter by engaging in a war of aggression. Moscow should be held accountable for its unlawful invasion of Ukraine. Nonetheless, as a belligerent in an international armed conflict, Russia has certain rights and obligations that must be acknowledged by the international community. While Russian attacks on Ukrainian civilian ports and grain infrastructure may contribute to global food insecurity, States that adhere to the “war-sustaining” logic in defining military objectives should temper their criticism of Russia’s actions. Condemning such attacks today could be used in future conflicts by other adversaries, like China, to discredit similar acts of economic warfare.
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Raul (Pete) Pedrozo is the Howard S. Levie Professor on the Law of Armed Conflict at the Stockton Center for International Law, U.S. Naval War College, Newport, Rhode Island.
Photo credit: Unsplash
