The Russian warship Caesar Kunikov (pictured above) had been in several conflict situations throughout its commission, including being deployed off the coast of Syria during Russia's 2008 war in Georgia.

But on Wednesday night, the Ukrainian army announced on Telegram that the 112-meter (367-foot) warship had been sunk off the coast of the Crimean peninsula. Ukraine's intelligence services released a video of the incident in which an explosion is followed by a raging fire onboard the vessel.

The sinking was certainly not Ukraine's first military success on the Black Sea, a crucial battleground in its war against Russia. Whereas both sides are fighting to a standstill on land, Ukraine has been able to break Russia's naval supremacy at sea.

Escaping Russia's chokehold one step at a time

That is not how things looked when Russia launched its full-scale invasion of Ukraine in February 2022. The numbers suggested that Russia held a massive military advantage over its neighbor. Its Black Sea Fleet quickly sealed off Ukraine's harbors, captured strategically important Snake Island off the coast of Romania and mined large swaths of of the sea, seemingly cutting Ukraine off from the rest of the world.

But little by little, Ukraine has freed itself from Russia's naval chokehold. The first step came in April 2022, with the sinking of the Moskva, the flagship of the Russian Black Sea Fleet. Then came the recapture of Snake Island in July of 2022. Russian ships, ports and supply routes were routinely attacked.

In Juli 2023, Ukraine attacked the Kerch Bridge, which connects the occupied Crimean peninsula to mainland Russia, leaving it badly damaged.

In October 2023, Russia was ultimately forced to withdraw most of its fleet from Sevastopol into the Black Sea's eastern waters. Yet even there, their warships remain vulnerable, as was seen when Ukraine was able to badly damage a landing craft in the port of Novorossiysk some 300 kilometers (186 miles) east of Sevastopol.

Ukraine's successes "show that the Russians can't adequately protect themselves against Ukraine's anti-ship and drone artillery," said Stephen Blank, Eurasia analyst at the Washington-based Foreign Policy Research Institute, in a September 2023 interview with DW. "More than that, they don't seem capable of answering the threat Ukraine poses to them." 

Statistics from the Center for Strategic and International Studies (CSIS), a Washington think tank, show Russia has lost around 40% of its Black Sea naval tonnage since February 2022, wrote retired US Marine officer and CSIS senior advisor Mark Cancian in a guest commentary published in Foreign Affairs magazine earlier this month. But how was that possible?

Ukraine's 'creative' use of drones and rockets

Ukraine achieved these military victories with an unusual combination of weapons, Cancian wrote. Part of its arsenal consists of anti-ship missiles — some produced domestically, others provided by Western allies — with a range of up to 200 kilometers. These were designed to be launched at sea, but the Ukrainian army has modified them to be fired from protected areas on land, making them less vulnerable to counterattack.

Ukraine has also been effectively using another type of long-range missile provided by Western allies to attack moving targets at sea, even though it is designed for attacking static targets on land. Ports, logistics centers and supply depots in Crimea have all been hit with them, as well as warships anchored in Russian ports.

Ukrainian naval drones — small, explosives-laden, crewless boats — have proven difficult to spot and defend against. These drones are reported to have a range of up to 800 kilometers. Video-outfitted and remote-operated, they can be used for any number of missions. They can also take evasive action when necessary and change targets at the last second if the initial target cannot be engaged.

Ukraine largely developed the Magura V5 naval drone on its own, refining it throughout the war. Now in serial production, these drones are often sent out in swarms, making them even more challenging to defend against.

Cancian said this inventive combination of different weapons systems is what has enabled Ukraine's military to sink or badly damage not only the Moskva and two more Russian frigates but also five landing craft tanks (LCTs) and a submarine. 

Important strategic advantages for Ukraine

In many regards, the Ukrainian military's successes have also alleviated pressure elsewhere. Early in the war, Russia's land campaign threatened the Odesa region.

Ukraine's ability to keep Russian vessels out of the Black Sea's western waters now, as Blank told DW, "makes it difficult for Russia to maintain its logistics capacity to resupply troops in the south of Ukraine." In turn, Ukraine has been able to send soldiers initially tasked with defending the southern part of the country to the eastern front for reinforcement.

These developments have also had a significant impact on Ukraine's grain exports. It was not until July 2022, that the United Nations (UN) could broker a grain agreement in which Russia lifted its naval blockade allowing a limited amount of Ukrainian exports to be shipped from Odesa. Yet, one year later, Russia withdrew from the agreement and threatened to attack any merchant vessels sailing for Ukraine.  

But the attacks never came. Though Ukraine had shifted a large quantity of its food exports to rail in the meantime, soon ships were again setting out across the Black Sea bound for the ports of Constanta and Istanbul — since December 2023, export volumes have even eclipsed those achieved during the UN-brokered grain deal.

Western military assistance remains essential

The shift of military balance on the Black Sea alone won't lead Ukraine to military victory. The situation on land is far too entrenched for that.

However, according to CSIS senior advisor Mark Cancian, it may allow Ukraine to negotiate from a more powerful position should peace talks with Russia ever materialize. Until then, however, Ukraine remains dependent upon its Western partners for arms, especially missiles and artillery ammunition.

That is the only way Ukraine's military can continue to hold Russia's Black Sea fleet in check. Otherwise, Ukraine's astonishing successes at sea could all be quickly undone.

This article was translated from German by Jon Shelton