ISW 12/15:Ukrainian's UUV for the first time in NAVY HISTORY

https://understandingwar.org/research/russia-ukraine/russian-offensive-campaign-assessment-december-15-2025/

Russian forces continued offensive operations east of Velykyi Burluk toward Obukhivka and southeast of Velykyi Burluk toward Kolodyazne on December 14 and 15 but did not advance.

Russian forces continued offensive operations in the Kupyansk direction on December 15 but did not advance.

Russian forces attacked southeast of Borova near Novoyehorivka on December 14 and 15 but did not advance.[50]

Russian forces continued offensive operations in the Slovyansk-Lyman direction on December 15 but did not advance.

Russian forces continued offensive operations in the Dobropillya tactical area on December 15 but did not advance.

Russian forces continued offensive operations in the Pokrovsk direction on December 15 but did not advance.

Russian forces continued offensive operations in the Novopavlivka direction on December 15 but did not advance.

Russian forces continued offensive operations in the Oleksandrivka direction on December 15 but did not advance.

Russian forces continued limited ground assaults in the Kherson direction on December 15 but did not advance.

 

Russian forces continued offensive operations in northern Sumy Oblast on December 15 but did not make confirmed advances.

 

Russian forces continued offensive operations in the Siversk direction on December 15 but did not make confirmed advances.

 

Russian forces continued offensive operations in the Hulyaipole direction on December 15 but did not make confirmed advances.

 

Russian forces continued offensive operations in northern Sumy Oblast on December 15 but did not make confirmed advances.

 

Key Takeaways

1. US, Ukrainian, and European officials reportedly agreed on unspecified security guarantees for Ukraine during a peace negotiation meeting in Berlin, Germany, on December 15.
2. Ukrainian forces conducted an unmanned underwater vehicle (UUV) strike against a Russian submarine for the first time in naval history on the night of December 14 to 15.
3. Ukrainian forces continue counterattacking in the Kupyansk direction as Russian ultranationalist milbloggers acknowledge the severity of the situation for Russian forces.
4. Russian forces are striking Ukrainian logistics lines in Odesa Oblast with various air launched munitions, including glide bombs, highlighting Ukraine’s urgent need for a well provisioned and diverse air defense umbrella.
5. Russian strikes appear to be advancing the Kremlin’s stated goal of degrading Ukraine’s energy infrastructure by splitting Ukraine’s power grid in half. Ukraine requires Western-provided air defense systems and partner support for its drone interceptor development to safeguard itself against increasingly devastating strikes on its energy infrastructure.
6. Ukrainian forces recently advanced in western Zaporizhia Oblast. Russian forces recently advanced in the Kostyantynivka-Druzhkivka tactical area.