Ukraine's attacks in Crimea are 'degrading' Russia's Black Sea Fleet, but have not defeated it: ISW

• Russia's Black Sea Fleet has been weakened in Crimea, but not defeated, per a US-based think-tank.
• Many of its vessels are withdrawn, but it's premature to say the fleet is beaten, said the ISW.

Ukraine's campaign of strikes on Russian military assets in Crimea has been "degrading" Moscow's Black Sea Fleet but hasn't defeated it, according to the Institute for the Study of War.

While the Black Sea Fleet has been weakened in its role as a combined arms headquarters, many of its assets can still be used to fight the war, the US-based think tank wrote in a special assessment on Sunday.

"Strikes on Black Sea Fleet assets are degrading its role as a combined arms headquarters but have not defeated it as a naval force," it wrote.

The Black Sea Fleet might sound like a naval-only formation, but it's actually a "major combined arms formation" with surface-to-surface missile batteries, air defenses, and infantry, the ISW added.

Ukraine hammered the Black Sea Fleet in September with a series of long-range missile strikes and drone attacks, hitting a shipyard, a fleet headquarters in Sevastopol, and docked warships.

The attacks appear to be working. Russia earlier this month pulled back two frigates, three submarines, five landing ships, and several smaller vessels from Sevastopol.

But it's too early to tell if the Black Sea Fleet has truly been crippled, the ISW wrote.

"Ukrainian strikes against BSF naval assets and repair facilities in Crimea may be preventing BSF naval elements from fully conducting their desired missions," wrote the think-tank. "Though BSF elements remain capable of conducting most wartime operations, and assertions Ukraine has driven away or defeated the BSF are premature."

The withdrawal is still likely a significant win for Ukraine, according to the ISW's assessment. Russia has lost much of its ability to blockade a shipping corridor established by Ukraine this summer in the Black Sea, which is vital to Ukraine's economy.

And Ukrainian strikes are inflicting serious damage to some Russian airfields and air defenses, softening up Crimea for a potential fresh wave of attacks, wrote the think-tank.

All of this has weakened Crimea's potential as a "springboard" for Russia's operations in southern Ukraine, where Moscow has for months been trying to stave off Kyiv's counter-offensive.

The Crimean peninsula, annexed by Russia in 2014, is used by the Kremlin as a staging area for the war in the south, and its rail lines and roads have been critical to transporting troops, equipment, and fuel to the Russian frontline, per the ISW.

Now, ground communications lines and logistics routes from Crimea to the frontline have been disrupted, or are exposed to Ukrainian attack, according to the think-tank.

Western aid, particularly the provision of long-range missile systems, has been key to this progress by Ukraine, the ISW noted.

"No single Western-provided system will provide Ukraine with a decisive advantage or directly enable Ukrainian victory, and this report does not assert that ATACMS or other systems would provide Ukraine with a silver bullet," it wrote.

"However, Ukraine is demonstrably degrading Russian forces and logistics in Crimea, and the Western provision of long-range missiles would enable further strikes on the Russian rear," it added.