Moscow: Two days after Ukrainian President Volodymyr Zelenskyy cautioned civilian airlines about the peril of operating in Russian airspace, a wave of flight cancellations, airport closures, and other significant disruptions have been reported throughout Russia. According to Radio Free Europe Radio Liberty, Ukraine's intensified drone campaign against Russia has been causing such disruptions for an extended period. However, Zelenskyy's recent remarks hinting at an escalation have sparked inquiries into how severely Ukraine can impact Russian aviation. Valeriy Romanenko from Ukraine's Museum of Aviation stated, "We are not talking now about the temporary disruption of operations, but about blocking them 24/7." Romanenko explained that the strategy involves making Russian airports unusable by diverting Russian air defense assets, while Ukraine employs small drones for the operation. This statement follows Zelenskyy's video address on September 1, where he warned airlines about the dangers of using Russian ai rspace. Following Zelenskyy's caution, Ukraine officially notified the International Civil Aviation Organization (ICAO) on September 2, warning of escalating risks to civil aviation in Russian airspace. This was underscored by the events on September 3, as Moscow's Vnukovo Airport temporarily halted operations. The city's other major airports, Sheremetyevo and Domodedovo, also announced restrictions. Moscow Mayor Sergei Sobyanin reported that 548 Ukrainian drones flew toward the Moscow region between September 2 and 3. In response, Russia's Transport Ministry clarified safety measures to foreign airlines at Russian airports and in Russian airspace. Transport Minister Andrei Nikitin stated that Russia is collaborating with the Defense Ministry and National Guard to minimize the impact, although Flightradar24 data indicated that four Russian airports were among the world's five most disrupted on September 3. Romanenko suggested that Ukraine's strategy to escalate pressure without targeting civilian aircraft could involve additional measures, such as striking Russia's air-traffic-control infrastructure, including control towers, automated landing systems, and radar systems. Alexander Lanetsky, CEO of Friendly Avia Support, noted that paralyzing Moscow's airspace would have a nationwide impact, leading to declared no-fly zones and severely disrupting the aviation sector. September 3 flight data indicated that the disruptions primarily affected domestic flights, highlighting the economic strain on a country spanning 11 time zones. Russia's international traffic, especially to Europe, has been significantly reduced due to Western sanctions following its 2022 invasion of Ukraine. However, flights to Turkey, Uzbekistan, the United Arab Emirates, China, and Egypt still account for a significant portion of Russia's international passenger traffic, according to the Association of Tour Operators of Russia (ATOR). Bohdan Dolintse, an aviation and defense technology expert, emphasized that airlines must assess threats whe n deciding to fly to Russia, as any loss of an aircraft in Russian airspace would be the responsibility of Russia and the respective airline.