Snake Island, or Serpents Island (Ostriv Zmiinyi in Ukrainian; Insula Serpilor in Romanian) is an islet off Ukraine’s southwestern coast and near the Danube Delta in the Black Sea. With a surface of 17 ha, the islet became a major flashpoint between the Ukrainian Operational Command-South and the Russian Navy, following the Russian seizure of Snake Island on 24 February 2022. Persistent Ukrainian counterstrikes forced Russia to retreat on 30 June 2022, ending a 127-day occupation. Following Ukraine’s victory, many have questioned the military and political value of the bitterly contested island. Our analysis seeks to shed light on Snake Island’s multilayered significance in the Black Sea and Odesa theaters of operations. 

KEY JUDGEMENTS 

I. Occupied in the opening hours of the invasion on 24 February 2022, Snake Island held, and still holds, kaleidoscopic importance for Moscow’s objectives in southwestern Ukraine and the Black Sea, including against NATO. Snake Island’s significance spans across all three levels of war – tactical, operational, and strategic – and serves three goal lengths, as follows: 

a.Short-term: Support the Odesa Offensive and Anti-Shipping Mission. 

  • Secure the seaway to the Ukrainian shoreline in preparation for Russia’s planned amphibious assault on Odesa- part of the failed Operational Direction-Southwest (OD-SW). 
  • Seize key maritime terrain to support the interdiction of the Odesa-Bosphorus shipping lanes and subsequent blockade of Ukraine’s port. 

b. Medium-term: Become a thorn in NATO’s Southeastern Flank. 

  • Establish a SIGINT listening station (COMINT and ELINT included) to monitor NATO activities in SE Romania. 
  • Expand offensive potential: kinetic effectors and electronic warfare (EW) systems.

c. Long-term: Seize lucrative offshore gas platforms located in NATO member Romania’s Exclusive Economic Zone (EEZ). 

  • Contest and claim parts of Romania’s EEZ, which has an estimated potential of 200 billion cubic meters of natural gas. The XIII Pelican, EX-27 Muridava, and EX-28 EST Cobalcescu concessions are likely targets. The development of the Black Sea gas fields would make Romania the European Union’s biggest natural gas producer and, inherently, a competitor to Russian gas. 
  • Russia has similarly captured all energy-rich parts of Ukraine’s EEZ since “little green men” annexed Crimea in 2014. Extending into new reserves aligns with Russia’s plans to assert military and economic dominance over the Black Sea.

 

II. Ukraine’s constant barrage of missile and artillery strikes successfully extirpated the Russian presence on Snake lsland. Bayraktar TB-2 combat drones conducted at least ten kinetic operations and were involved in a number of ISR and fire control taskings. The R-360 Neptune and Harpoon anti-ship missiles (AshMs) also played a key role, countering the Russian Navy’s sea-lines-of-communications (SLOC) and sinking at least six vessels, including the Russian Black Sea Fleet (BSF) flagship Moskva. At least one manned aircraft strike was recorded and featured a low-altitude bombing by a pair of Su-27s (AFIC/NATO Reporting name: Flanker). Artillery systems such as the homegrown 2S22 Bohdana were responsible for putting the last nail in Russia’s coffin, decimating the man-made infrastructure on the island until the occupiers were left with no physical cover. 

III. It is imperative that Russia does not re-capture Snake Island, even at the cost of the island becoming “no man’s land .” At the time of writing, Snake Island is in limbo – vacated by the Russians, re-claimed by Ukraine, but not yet re-garrisoned. Even if Ukraine does not create an outpost on the island, keeping the key maritime terrain from Russia’s hands is enough to deny Moscow’s original objectives. 

Change detection analysis of Snake Island pre-invasion (Google Earth imagery from 2016) and post-withdrawal of Russian forces (30 June 2022). Imagery credits: Maxar Technologies; annotated by T-Intelligence.

SHORT-TERM OBJECTIVES: ODESA OFFENSIVE AND ANTI-SHIPPING MISSION

SECURE SEAWAY FOR ODESA OFFENSIVE a.k.a OD SW

1. Russia seized Snake Island from Ukrainian forces to secure the SLOC in preparation for an amphibious assault on Odesa- part of the Odesa offensive, designated Operational Direction Southwest (OD-SW). A Russian Navy (RuN) surface action group led by the now-sunk Slava-class Moskva was in charge of the operation, which took place in the early hours of February 24. Immediately after the takeover, Russian marines garrisoned the island to deny key maritime terrain to Ukraine and exploit its tactical-operational value.

2. Russia started to turn Snake Island into an expeditionary outpost in support of the maritime component of OD-SW. Russian forces had anchored patrol boats near the island and, also pressed by Ukrainian air strikes, deployed short-range air defenses (SHORAD). In addition, Snake Island could have been used to base forward arming and refueling points (FARP) to boost sortie rate and repetition during air-naval attacks on Odesa and naval intelligence, surveillance, and reconnaissance (ISR) assets.

3. The collapse of OD-SW in the steppes of Kherson operationally “orphaned” Snake Island. Ukraine’s Operational Command-South (OC-S) defeated the Russian Southern Military District (MD) grouping at Mykolaiv and Voznezensk and drove the invaders down to Kherson city in mid-March 2022.

Assessed Russian OD-SW map, reprinted from “Target Transnistria: Russia’s Maskirovka and Pathways to Escalation (Threatcast)” (T-intelligence)

4. Russia’s follow-on plans for Snake Island largely depended on capturing the Odesian littoral. Russian control of the shoreline would have secured Snake Island from land-based threats. But with OD-SW in shambles and the Odesian coast still under Ukrainian control, the Russian garrison on Snake Island became a fixed, vulnerable target. The new situation likely prompted Sevastopol commanders to effect a cost-benefit analysis of abandoning versus defending the island, with the top brass opting for the latter. As Ukraine’s OC-S started lashing back with air, artillery, and anti-ship missile strikes at Snake Island, the Russian forces were forced on the defensive.

5. Sevastopol’s attempt at holding Snake Island despite the terrain entering a state of tactical limbo indicates operational stubbornness, continued interest in the Odesa offensive as a later option, and commitment to longer-term political objectives. The latter point rendered Snake Island a politically-charged issue, which most likely influenced Sevastopol’s decision to stay.

TOLLBOOTH TO INTERDICT MARITIME SHIPPING

6. The secondary objective of Russia’s designs on Snake Island was to augment the BSF in interdicting the shipping lanes to and from Ukraine. Part of this plan was to deploy land-based anti-ship missiles, coastal surveillance radars, and naval ISR assets on Snake Island. There were also indications of plans to base fast patrol craft out of the island. While BSF warships and naval aviation are primarily conducting the anti-shipping mission, a sensor-effector pair on Snake Island could have provided an additional layer to Russia’s maritime construct.

Annotated screenshot of MarineTraffic.com density map (T-Intelligence). As the map shows, Snake Island overlooks the main trade artery in the western half of the Black Sea.

7. Snake Island never got to contribute to the anti-shipping mission as the Russian occupants were busy surviving Ukraine’s constant barrage of missile and artillery strikes. Based on open-source reporting, Ukraine conducted at least 16 separate attacks on Russian positions between March and late June. Bayraktar TB-2s initially spearheaded ten kinetic operations and were involved in a number of ISR and fire control taskings. The R-360 Neptune and Harpoon anti-ship missiles (AshMs) also played a key role, countering the RuN’s SLOCs, and sinking at least six vessels, including the BSF flagship Moskva. At least one manned aircraft strike was recorded and featured a low-altitude bombing by a pair of Su-27s (AFIC/NATO Reporting name: Flanker).

Artillery systems such as the homegrown 2S22 Bohdana were responsible for putting the last nail in Russia’s coffin, decimating the man-made infrastructure on the island until the occupiers were left with no physical cover. 

8. In response to Ukraine’s hammering, Sevastopol rushed 9K35 Strela-10 (SA-13 Gopher), Pantsir S-1 (SA-22 Greyhound), and Tor-M2 (SA-15 Gauntlet) SHORADs along with ZU-23-2 anti-aircraft (AA) guns to the island, but with little effect. Ukraine destroyed most of the AA guns and SHORADs, especially the first batches of Strelas. With just 17 ha to rove around to escape Ukrainian targeting, the SHORADs were likely more offline than active and therefore suppressed. 

9. The loss of Snake Island had little effect on Russia’s anti-shipping mission, which continues to be spearheaded by BSF surface action groups and naval aviation. Ukraine’s increasingly diverse and lethal coastal artillery and multi-rocket launcher systems (MLRS), often paired with unmanned aerial vehicles (UAVs), have re-shaped the BSF’s risk assessment. Early signs indicate that Russian vessels are now forced to operate at arm’s length from the Ukrainian littoral. 

MEDIUM-TERM OBJECTIVES: LISTENING STATION AND OFFENSIVE POSTURE

LISTENING STATION

10. Left unchecked, the Russian occupation could have filled Snake Island with antennas, direction-finders, and other technical equipment to collect Signals Intelligence (SIGINT) on key military facilities in NATO member Romania’s southeast (SE). Just 40 km from Romania, the unrealized Snake Island listening station would have likely pointed its antennas at Mihail Kogalniceanu and Fetești air bases and command & control (C2) nodes to collect Communications Intelligence (COMINT). Electronic intelligence (ELINT) would have been an equally valuable objective, with specialized equipment attempting to collect, analyze and classify Romanian and NATO radar emissions to paint what is known as EOD, or electronic order of battle. An EOD typically contains the location of radars, frequencies, and operating bands used by said radars, emission signatures, etc. 

11. Russia had already deployed some SIGINT equipment to Snake Island, according to the Secretary of Ukraine’s National Security and Defence Council (RNBO) Oleksii Danilov. The same source says that Russia already leveraged Snake Island’s position to monitor communications in Odesa province and Transnistria – read more about the breakaway region in our recent threatcast. 

ENHANCED OFFENSIVE POSTURE

12. It is likely that Russia would have also sought to expand the island’s offensive potential with the deployment of a few but suitable systems in time. MLRS could have been a likely candidate to build up the island’s offensive posture, providing an attritable but effective firing solution. The BM-30 Smerch, with its assortment of 300mm rockets and warheads, can strike areas 90 km away. More high-end systems such as the K-300P Bastion (SS-C-5 Stooge) could have also been considered. Packing a double-punch against land targets and ships 300 km away, Bastion is uniquely suited for coastal-based engagements. However, the island’s small and complex surface would have posed a continuous limitation regarding build-up potential (i.e., number of systems) and system survivability (limited shoot-and-scoot).

13. Besides kinetic effectors, Electronic Warfare (EW) systems would have been some other logical candidates for beefing up Russia’s offensive posture. Examples are the Krashuka, 1L22M Avtobaza-M, and Repellent-1. With a powerful electronic attack (EA) capability, Russia’s EW systems can jam communications, navigation systems such as GPS, and drone down/up-links, to ranges in excess of 250 km. Some systems like the Krashuka-4 can even jam spy satellites in the Low-Earth orbit (LEO). Russian EW systems have been present in Ukraine since the early days of the invasion, with some being captured and destroyed by Ukrainian forces. 

LONG-TERM OBJECTIVE: BLACK SEA ENERGY THEFT

14. The Kremlin’s long-term goal was, and likely still is, to leverage Snake Island’s position to contest Romania’s energy-rich exclusive economic zone (EZZ), which holds an estimated 200 billion cubic meters of gas. We assess with a high degree of confidence that Russia would have rejected the 2009 Hague ruling on the Ukrainian-Romanian Snake Island dispute. 

ICoJ litigation maps. Left shows the Romanian vs Ukrainian claims / Right shows the ICoJ agreed maritime boundary between the Romanian and Ukrainian EEZs (All rights reserved ICoJ 2009)

Key Background In 2004, the Romanian government asked the Hague International Court of Justice (ICJ) to rule on the maritime boundary between Ukraine and Romania. The decision depended on whether the ICJ defined Snake Island as an island, part of Ukraine’s continental shelf, or an islet (i.e., “a rock” in Romania’s terms). In 2009, the ICJ ruled that Snake Island was too far from the seashore (Odesa) and small to constitute a benchmark in setting boundaries. The ICJ ruling satisfied 80 percent of Romania’s claims over the continental shelf and placed 9,700 square kilometers of waters under Bucharest’s control.  

15. Russian claims over Romania’s EEZ are difficult to threatcast but would most likely include at least the gas fields closest to Snake Island: 

  • XIII Pelican: gas potential confirmed (discovery wells are yet to be appraised). Black Sea Oil & Gas (BSOG), which is owned by Carlyle International Energy Partners and the European Bank for Reconstruction and Development, holds the majority package to XIII Pelican.
  • EX-27 Muridava: gas potential confirmed and estimated at 169 billion cubic feet. British company Petroceltic holds the majority package. 
  • EX-28 Nicolae Colbacescu: gas potential confirmed and estimated at 404 billion cubic feet. Muriadava and Colbacescu are underexplored and believed to hold more oil and gas deposits. Estimates for the two concessions are extracted from the 2013 Petroceltic annual results presentation and could be dated. 

Gas concessions in Romania’s and Bulgaria’s EEZ (all rights reserved IHS Markit). Snake Island is seen as a small dot north of the XIII-Pelican concessions.

Key Background: The development of the Black Sea gas fields would make Romania the European Union’s biggest natural gas producer, according to the Oil and Gas Employers Federation (FPPG). Romania would not only become self-sufficient* but also compete in the natural gas market with Russia. Romania currently imports less than most European Union members (nearly 21 percent). 

16. The most likely course of action would have been for RuN warships to ascertain de facto control over the targeted gas fields and escort Russian drillships to start exploitation. Sevastopol can profit from the Romanian Navy’s inability to police its waters following decades of underinvestment. From a political standpoint, the Kremlin would most likely leverage the grey zone nature of EZZs in the context of NATO’s Article 5. EEZs do not constitute territorial waters, and disputes over offshore energy deposits exist even within the Alliance (e.g., Turkey-Greece). However, Russia will probably tread lightly and probe NATO unity and Western European/North American commitment to the Black Sea states. 

17. Due to the Montreaux Convention, NATO cannot establish a permanent, large-scale naval presence in the Black Sea. However, NATO assists Romania (and Bulgaria) through periodic port visits by individual warships or joint fleet units called NATO Standing Maritime Groups. NATO Enhanced Air Policing is another means to protect Romanian interests in the Black Sea, especially if the fighter units are also outfitted for anti-shipping. Despite continuous Allied support, local allies must do the heavy lifting through defense procurement to be able to police their territorial waters and EZZs. 

18. Russia took over all energy-rich parts of Ukraine’s EEZ in a similar manner since “little green men” annexed Crimea in 2014. The Tavrida gas platforms, nearly 10 km east of the Snake Island, are one of the most forward-positioned offshore energy platforms that Russia has stolen from Ukraine. Ukraine recently hit the Tavrida gas platforms with two AshMs. Extending into new reserves aligns with Russia’s plans to assert military and economic dominance over the Black Sea.

19. Russia can still deter Bucharest from extracting gas from the Black Sea and attack (overt or cover) Romanian offshore energy infrastructure and drillships. RuN Spetsnaz units, subordinated to the Main Intelligence Directorate (GU), are uniquely qualified to conduct deniable attacks against drillships, offshore platforms used for housing and logistics, and oil rigs. Russian warships can stage shows of force and engage in a slate of other intimidation tactics, for example, exercises with subsequent notice to mariners/airmen (NORAM/NOTAM) that cover parts of Romania’s EEZ. If such provocations continue, Russia may discourage foreign investments in Romania’s offshore gas fields and prevent drilling activities completely. 

20. Russian warships have already shadowed Romanian gas platforms in June 2022, telegraphing a not-so-veiled reminder of Moscow’s ambitions in the Black Sea. It is imperative that Russia does not re-capture the island at any given time. Even if Ukraine does not establish an outpost on the island, keeping the key maritime terrain from Russia’s hands is enough to prevent Moscow from achieving its medium to long-term objectives in the western Black Sea. Snake Island is a fitting example of how even a tiny Russian land grab has far-reaching implications for Euro-Atlantic security. 

by HARM

This assessment was made using Open-Source Intelligence (OSINT) techniques and resources. Visit Knowmad OSINT to learn more about our online OSINT training. 

DISCLAIMER: This report is legacy content published before T-Intelligence’s relaunch on 4 July 2023. The report has been retained for archival purposes, but the content may not align with current standards.

Vlad Sutea

Founder of T-Intelligence. OSINT analyst & instructor, with experience in defense intelligence (private sector), armed conflicts, and geopolitical flashpoints.

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