In 2014, Ukrainian Defectors Formed A New Russian Brigade. In 2022, The Ukrainian Army May Have Destroyed It.

When Russian troops invaded Ukraine’s Crimean Peninsula in February 2014, the Ukrainian military forces on the strategic peninsula in the Black Sea mostly melted away. But thousands of Ukrainian troops surrendered—and many of them defected.

When an estimated 700 members of a Ukrainian marine brigade changed sides, the Kremlin saw an opportunity. It re-equipped the defectors and folded them into a new Russian navy coastal-defense brigade.

The 126th Guards Coastal Defense Brigade … didn’t last long. It reportedly is one of the victims of the Ukrainian military’s month-old counteroffensive in southern Ukraine. A counteroffensive that quickly is building momentum.

The 126th GCDB is—was—unique. And not only for the hundreds of defectors who filled its billets. While all the Russian navy’s regional fleets have marine battalions and brigades for coastal operations and amphibious assaults, the 126th is the only coastal-defense brigade.

Its three infantry battalions, single tank battalion and supporting engineer, air-defense and artillery units—together amounting to around 2,000 troops—in form and function are, or were, more akin to an army formation than they are a marine formation. The 126th Guards Coastal Defense Brigade is the navy’s army.

Technically, the 126th GCDB belongs to the Russian navy’s Black Sea Fleet, which sails from Sevastopol in occupied Crimea. Its job, in peacetime, is to safeguard the Black Sea Fleet’s extensive infrastructure on the peninsula.

But when Russia widened its war on Ukraine starting in late February, the 126th GCDB rolled into southern Ukraine under the banner of the Russian 22nd Army Corps, a grouping of two naval brigades and supporting battalions.

Striking north from Crimea, the invaders quickly captured the port of Kherson then barreled toward Mykolaiv, where they ran headlong into stiffening Ukrainian defenses. The 126th GCDB suffered heavy casualties around the city of Voznesensk. The Russians pulled back from Mykolaiv, ultimately consolidating their lines just north of Kherson.

The southern front froze, for months, with neither side making any big moves. Then in May, the Ukrainian army—newly re-armed with American-made rocket-launchers—began plucking at the supply lines across southern Ukraine, gradually eroding the strength of the 22nd Army Corps and the adjacent, and much bigger, 49th Combined Arms Army.

Four months later in the last week of August, Ukrainian brigades attacked south from multiple lodgements along the southern front line, including a hard-won bridgehead on the left bank of the Inhulets River. Kyiv planned this southern counteroffensive to coincide with a separate counteroffensive in the east.

The eastern attack moved quickly. The southern attack, by contrast, took a few weeks to get traction on the open landscape of the country’s southern breadbasket—difficult terrain for any attacker.

The Ukrainians in the south advanced along at least three axes. The Ukrainian army’s 17th Tank Brigade rolled toward Kherson from the west, while the Ukrainian navy’s 35th Marine Brigade punched south from the Inhulets bridgehead and the army’s 128th Mountain Brigade marched south along the wide Dnipro River.

In the eastern sector of the southern front, between the Inhulets and Dnipro, Ukrainian forces met the 126th GCDB—and found it weak. The brigade’s troopers reportedly had been in their foxholes for six months with no relief, and with fewer and fewer supplies owing to Ukrainian deep strikes on bridges, railways and depots.

Plus, the Kremlin was counting on the 126th GCDB to defend apparently hundreds of square miles. “The front line is stretched so thin that some villages in this sector have 15 men defending them,” the Washington, D.C.-based Institute for the Study of War reported.

The coastal-defense brigade didn’t last long. On Oct. 2, there were reports the 126th GCDB was routed. Two days later, reports claimed the brigade was degraded—if not destroyed.

Russian forces on the right bank of the Dnipro east of Kherson, including whatever remains of the 126th GCDB, appear to be falling back to Beryslav, which should give them easy access to a durable river crossing should they need to retreat to the left bank of the Dnipro and exit the battlefield.