Numerous Ukrainian strikes on Russia's frontline air defenses created a dilemma for Moscow - leave its troops exposed or pull replacement systems from Russia, exposing deep rear facilities.
Serhii Zgurets, head of Defense Express, says Russia has exhausted all conventional weapons except nuclear arms, contradicting Putin's vow of retaliation for Ukraine's drone strikes on critical military facilities in Tatarstan.
Multiple drones struck an industrial facility and luxury high-rises in Kazan on Saturday, forcing authorities to evacuate factories and close three regional airports.