In its latest Russian Offensive Campaign Assessment, the institute said that despite Kyiv not claiming responsibility for the attacks on two Russian military airbases on Dec. 5, Ukraine could just have demonstrated its ability to strike deep inside Russian territory.
Its new capability might even interfere with Russia's mass missile attack campaign against Ukrainian civil infrastructure, the institute said.
Meanwhile, a senior Ukrainian official hinted on social media that Ukraine was indeed behind the attacks on Russian air bases - a third one of which, near Kursk, was hit early on Dec. 6.
"If something is launched into other countries' airspace, sooner or later unknown flying objects will return to (its launch) point," Ukrainian Presidential Advisor Mikhail Podolyak wrote on Twitter.
According to the Russian Defense Ministry and some "military bloggers", Ukraine attacked airfield Engels-2 in Saratov Oblast (about 315 miles from the border with Ukraine) and the airfield in Dyagilevo in Ryazan Oblast (about 285 miles from the border with Ukraine) with UAVs. Both airbases are used to house Russian strategic bombers, which Russia has used to launch cruise missiles at Ukraine.
Russian media reported damaged strategical bombers at the Engels-2 airbase and a destroyed fuel truck at the Dyagilevo airbase.
Read also: General Staff reports effective attacks on invaders' positions in Ukraine
Despite Russia mounting another wave of mass missile strikes on the energy infrastructure of Ukraine on Dec. 5, Russian "milbloggers" were not triumphal as usual, but seized by anger over the Russian military's apparent inability to prevent Ukrainian strikes on its military airbases deep in Russian territory.
Although Russian military airfields are obviously possible targets for Ukraine's strikes or for the activity of sabotage and reconnaissance groups, the "milbloggers" claimed they weren't protected sufficiently. They also called to intensify counter-terrorism measures within Russian territory.
"Select milbloggers suggested that the strikes on Engels-2 and Dyagilevo Air Bases threaten Russia's legitimacy as a nuclear power, as the strikes damaged aircraft capable of carrying multiple nuclear weapons."
Russian military bloggers also think the Russian military doesn't take into account their data as a reliable open-source intelligence (OSINT).
ISW key points:
Russian forces continue to defend their positions on the line between Svatovo and Kreminna in Luhansk Oblast;
Russian forces have made some gains near Bakhmut in Donetsk Oblast, and continue to try to encircle the city - so far without success. They are focusing their offense efforts near Avdiyivka;
Russian occupying "authorities" continue to kidnap children from Donetsk and Luhansk oblasts, taking them to Russia. Many of the children need medical aid and care;
Russian troops shelled over 20 settlements on the western bank of the Dnipro River in Kherson Oblast;
Ukrainian intelligence reported that Russia is going to launch an electronic database with personal data of all servicemen, including travel restrictions, in February 2023.