The Ukrainian 3rd Army Corps' Operation Vivaldi—its secretive counteroffensive east of Sloviansk in northern Donetsk Oblast—started earlier than first reported, and by the time it ended on 14 October it had cost the Russians more than 8,000 troops, by the 3rd Army Corps' count.

It was a major Ukrainian victory in one of the most important sectors of Russia's 56-month wider war on Ukraine. But it could prove to be a temporary win, one the Russians may be able to partially reverse, if the administration of US President Donald Trump continues to throttle Starshield, the military version of Starlink that Ukraine's drones and commanders rely on.

The Ukrainians' former command and control advantage, largely attributable to once-reliable Starlink and Starshield access, was pivotal as Operation Vivaldi played out in the Donbas region in stages starting in March. That advantage shrank practically overnight on 14 October, when a new speed cap began cutting off Ukraine's Starshield terminals whenever they moved faster than about 160 km/h (100 mph).

The 3rd Army Corps attacked east of Sloviansk and north of Lyman as early as March, analyst and mapper Clément Molin concluded after scrutinizing official videos and interviews the Ukrainian defense ministry recently released. "The operation began much earlier than initially thought," Molin wrote.

We are now 5 months after the start of Ukraine's Vivaldi operation and it has now officially ended

A month after the operation was revealed, we know have much more information on the biggest Ukrainian success of the year.

THREAD1/18 pic.twitter.com/MgCoSv7Yhr

— Clément Molin (@clement_molin) October 20, 2026

The timing was probably no accident.

In early February, SpaceX, working from a Ukrainian defense ministry whitelist, switched off the thousands of stolen and smuggled Starlink terminals the Russians had been using.

That had the effect of grounding many Russian drones and blinding many Russian commanders. Taking advantage of the Russians' confusion, Ukrainian troops attacked in several key sectors: in Zaporizhzhia and Dnipropetrovsk Oblasts in the southeast, and east of Sloviansk in northern Donetsk.

The Donetsk attack expanded into a full-blown counteroffensive under conditions of strict secrecy as the 3rd Army Corps probed for weaknesses along the flanks of the Russian 20th and 25th Combined Arms Armies, then overextended along the axis between the Zherebets River in the east and the outskirts of the Sloviansk-Kramatorsk urban conglomeration in the west.

The Russians had been threatening to lay siege to Sloviansk and Kramatorsk, the last two big free cities in Donetsk Oblast, from two directions: the north and the south. Operation Vivaldi eliminated the northern threat—and at great cost to the Russian 20th and 25th CAAs.

Drones lead

Aerial drones and unmanned ground vehicles led the attack, taking the Russians by surprise. "For an offensive operation, the Ukrainians sustained relatively few casualties compared to previous engagements," Molin explained. "Conversely, the defending Russian forces suffered significantly higher losses, largely due to the rapid encirclement of at least three regiments, not all of which managed to escape the area."

It's unclear how many casualties the Russians suffered, but they might number in the thousands. The 20th and 25th CAAs were particularly fragile because the 3rd Army Corps and supporting drone units had been bombarding their supply line with so-called "middle strike" drones.

But many middle strike drones rely on civilian-style Starlink satellite terminals or the more rugged, better-performing Starshield. Now that the 3rd Army Corps has wrecked Russia's 144th Motor Rifle Division, which the Institute for the Study of War assessed on 20 October has effectively ceased to exist as an organized fighting force, and pushed the Russian survivors back to the far bank of the Zherebets River, the Ukrainians are probably "consolidating their gains and adopting a defensive posture," according to Molin.

But that defensive posture, protecting Sloviansk from a northern attack, depends on reliable communications and responsive drones. On 14 October, a new speed cap hit Ukraine's Starshield terminals, cutting the link on any drone flying faster than about 160 km/h. Who ordered it is disputed. Sources told Reuters the order came from inside the White House, and that Pentagon leaders were told the service needed to be slowed.

The Wall Street Journal reported that Musk himself ordered the slowdown, and that he and Trump discussed it soon after it became public. While Trump has denied ordering the speed limit, it's worth noting that the American president has become more overtly friendly toward Russia as his Republican Party looks likely to lose control of the US Congress in the November mid-term elections.

The speed limit renders many of the faster middle-strike drones unflyable. As a result, "Ukrainian drone strikes have diminished significantly following yesterday's crippling of Ukraine's Starlink/Starshield connections, Russian sources report," the military history account ChrisO_wiki wrote on X on 15 October, the day after the speed limit took Ukrainian operators by surprise.

A reduction in middle strikes on Russian supply lines could help Russian field armies recover from recent setbacks, including their retreat back across the Zherebets River. And if the communications confusion resulting from the partial loss of Starlink/Starshield connectivity persists, it could give the Russians the same kind of opportunity the Ukrainians had back in the spring.

An opportunity to go back on the attack—and an Azov communications engineer warned Euromaidan Press in February that the shoe might be on the other foot.

That's the worst-case scenario for the Ukrainians now that Operation Vivaldi has ended. The best case is that they get full Starlink and Starshield access back—or find command and control alternatives—and duplicate, in other sectors, the same success they enjoyed in northern Donetsk.

"Now that the northern flank of Donbas is secured, at least for some time, the focus will concentrate on the southern flank," Molin predicted.

Overnight on 14 and 15 October, the Ukrainian navy fired a clutch of Long Neptune cruise missiles at Borisoglebsk air base in Voronezh, in western Russia some 260 km from the border with Ukraine.

The results were devastating. The ground-launched Neptunes struck the tarmac where six Russian air force Sukhoi Su-34 fighter-bombers were parked nearly wingtip to wingtip in uncovered positions.

Satellite imagery from the morning of 15 October depicted piles of smoldering wreckage. The navy said it hit all six jets. Ukrainian President Volodymyr Zelensky said four Su-34s were destroyed and a further two were damaged. "I thank the warriors of the Ukrainian navy for their precision!" he wrote.

The jets, he said, were loaded with aerial bombs and ready for new strikes on Ukraine. An analyst reading the imagery counted wreckage of two to four aircraft and two empty spots where damaged jets had been moved.

An Airbus Pléiades satellite image from 11 October, four days before the strike, showed the six Su-34s on open aprons. Next to them were structures that the Russian independent outlet Istories said looked like anti-drone nets or their frames. Nets can snag a small drone. A cruise missile goes through.

At roughly $50 million apiece, by the Ukrainian Air Force's estimate, the four destroyed jets alone cost Russia some $200 million. The twin-engine, two-seat, supersonic Su-34 is the Russian air force's best fighter-bomber. Almost every day, Su-34s lob KAB precision glide bombs at Ukrainian troops and civilians.

Satellite images of Borisoglebsk Air Base as of October 15, 08:25 UTC

On the night of October 15, several Su-34 were destroyed at Borisoglebsk Air Base. pic.twitter.com/3ZNBWhU6UD

— AviVector (@avivector) October 15, 2026

In nearly 56 months of hard fighting in Russia's wider war on Ukraine, the Russians have now lost no fewer than 37 Su-34s destroyed, with several more damaged, by open-source counts. Sukhoi continues to deliver new Su-34s in small batches, the latest handed over on 7 October, helping the Russians sustain their overall inventory despite heavy losses.

They've still got plenty of Su-34s, but that doesn't mean the Russians shouldn't worry. As long as they're parking warplanes out in the open within range of Ukraine's best deep strike munitions, those planes are vulnerable to attack. Russia's air defenses are spread too thin to intercept every Ukrainian munition.

Satellite imagery showing the aftermath of a Neptune missile strike on six Su-34 fighter-bombers at Borisoglebsk Airfield.

Coordinates: 51.36315, 42.18560 pic.twitter.com/7TNpxGIaB0

— Dnipro Osint (@GarbuzYe) October 15, 2026

The strike may also hit the Russian air force's training pipeline. Borisoglebsk air base is home to the 160th Aviation Training Regiment. The regiment operates Yakovlev Yak-130 trainers for more basic flight training plus—for more advanced training—front-line combat aircraft including Su-34s, Sukhoi Su-35s, and Sukhoi Su-30s.

Russian bloggers are aghast, according to a round-up of posts on Russian social media by analyst ChrisO_wiki. "How is it that, four years after the start of the Special Military Operation, there are no protective structures for aircraft at airfields located within range of Ukrainian air strikes?" blogger Ramsay wrote. "And where did the billions of rubles allocated for their construction go?"

"Much can be said about the need to build a sufficient number of concrete shelters at all airfields," blogger Vladimir Romanov pointed out. "Reality shows that, to date, sufficient measures have not been taken."

Close parking

Ramsay asked why the Su-34s were concentrated in one area, apparently so that ground crews could quickly service all of them with a single ground power unit, a mobile generator that starts an aircraft's systems before flight. "How is it that the APA, a utilitarian piece of equipment, has become so scarce that it forces an entire group of combat aircraft to be parked in a single area, making them an ideal target for attacks?"

The best defense is an active one, however, the Fighterbomber channel stressed. "Protecting aircraft by the usual method of moving them out of the line of fire at such ranges from long-range strike systems won’t work here; the only way to defend against them is with a full-scale, echeloned air defense system—both ground-based and airborne."

1/ Russian warbloggers are furious at the news that a Ukrainian missile has destroyed between 4 and 6 Su-34 jets on the ground at a Russian airfield. How is it possible, they ask, that the Russian air force is still parking aircraft close together without protection? pic.twitter.com/BrTvfCMRfH

— ChrisO_wiki (@ChrisO_wiki) October 15, 2026

Ukrainian planners know this. Which is why, for more than a year now, they've been systematically striking Russian radars, surface-to-air missile batteries, and mobile air defense systems. By March, Ukrainian forces were “collaps[ing] the layered defensive architecture that the Russian integrated air defence doctrine depends upon to function,” according to an in-depth investigation by Tochnyi.info.

The strikes on Russian air defenses—at least 492 of them between June and early March—are part of a carefully scripted plan. Destroying the right air defenses faster than the Russians can replace them has the effect of “facilitating strikes on more critical targets deep within Russian territory,” Tochnyi.info explained.

The critical targets include air bases such as Borisoglebsk and the expensive warplanes parked on its tarmac.

On or just before Wednesday, 14 October, Russian Geran-4 one-way attack drones struck two more cargo ships—one in the Buh River Estuary near Mykolaiv and another in Chornomorsk, 20 km south of Odesa.

They're the latest strikes in competing Russian and Ukrainian countershipping campaigns that have, since this summer, throttled Black Sea grain exports.

The jet-propelled Geran-4s are Russia's weapons of choice for these ship strikes. The drones haul warheads of up to 90 kg at up to 500 km/h and can fly more than 700 km. They already had AI-assisted targeting, and the Russians recently added terrain-matching navigation to make them less reliant on satellites and harder to jam with signal-scrambling electronic warfare.

For months, the Geran-4s and other Russian munitions have pummeled Ukrainian ports and the ships hauling grain from them. But Ukrainian forces were actually the first to escalate the shipping fight in an effort to squeeze Russian logistics.

Russian Geran-4 jet-drones struck two more cargo ships, in the Buh River Estuary and at Chornomorsk Port in Odesa Oblast. pic.twitter.com/wOXcJFAj5O

— AMK Mapping (@AMK_Mapping_) October 14, 2026

As recently as early this summer, hundreds of Russian tankers and dry cargo ships plied the Black Sea and adjacent Sea of Azov, hauling fuel and bulk supplies between ports in Russia and Russian-occupied ports in southern Ukraine.

Most of the Russian vessels were unregistered and sailed without transponders, making them a kind of regional adjunct of Moscow’s “shadow fleet” that ships Russian oil and other goods to the global market in defiance of international sanctions.

Ukrainian drones had already hit ships hauling stolen Ukrainian grain out of occupied ports in June.

On 6 July, Ukraine’s deep strike drone force finally started hunting the rest of the Russian ships. By day eight of the countershipping effort, the Ukrainians had hit 105 vessels. By day 12, drones including AI-assisted Fire Point FP-1/2s had struck 159, even a few tugboats sent to assist the damaged tankers.

Just a few days after Ukraine launched its countershipping campaign, Russia launched a retaliatory campaign targeting Ukraine’s Black Sea grain ports as well as the ships, many of them foreign-flagged, that haul grain through Türkiye’s Bosporus Strait out to the Mediterranean Sea and onward to foreign ports.

Soon, the Russian shadow fleet’s hundreds of ships were either drifting, disabled, or sheltering in Russian ports. On the other side of the Black Sea, Ukraine’s lucrative grain trade was in a state of collapse. Ports were under constant attack. International shippers were increasingly reluctant to send their vessels into the Black Sea.

Trade freefall

Grain shipment figures on both sides tell a stark tale. According to the Russian Grain Union, in September approximately 1.36 million tons of wheat shipped from Russian ports, including ports on the Black Sea and Sea of Azov, compared to 5.4 million tons in September 2025—a 75% reduction.

Meanwhile, Ukraine exported 1.094 million tons of wheat in September, down from 2.051 million tons in September 2025—a 47% reduction. The only thing preventing further throttling of Ukrainian grain exports was Izmail, Renia, and Kilia—the country’s three small ports on the Danube River, which forms Ukraine’s southern border with Romania and flows into the western Black Sea a relatively short 435 km from the Bosporus Strait.

But the Russians were beginning to target the Danube ports and the grain ships heading to and from them, too. In October, Russian drones sank the Saint Kitts-flagged M/V Royad Mammadov, bound from Izmail to Ravenna, Italy, with Ukrainian grain, and the Togo-flagged M/V Alfa Watan, and damaged the Palau-flagged M/V Able, killing at least two seafarers.

“The Black Sea grain standoff, in which both Russia and Ukraine continue to suffer losses, persists,” Polish open-source intelligence analyst Thorkill wrote.

With global food prices rising partially as a result of the bottleneck in grain exports through the Bosporus, the United Nations and Türkiye have been trying to arrange talks between Russia and Ukraine regarding a possible Black Sea ceasefire.

A previous grain deal, brokered by Türkiye and the UN in 2022, collapsed a year later. Ukraine kept ships moving through its own corridor until Russian strikes shut it down this summer.

Update, 16 October: Drones hit at least four more merchant ships off Bulgaria and Romania between 13 and 15 October, sinking the HS Dignity off Krapets. At least 17 seafarers are missing. Romanian President Nicușor Dan called the attacks “attempts by Russia” to destabilize Romania and Bulgaria and said NATO’s North Atlantic Council would discuss them.