The strikes on the Ryazan refinery demonstrate Russia’s inability to provide the region with the necessary air defense capabilities. In particular, this is evidenced by last year’s attack on the Dyagilevo air base, according to Defense Express. The direct distance to the Ryazan refinery from the Ukrainian border is more than 450 km. “But despite the distance and the possibility of methodical strikes, the main marker of the real situation is the fact that the Dyagilevo air base is located in Ryazan,” the report says. This airbase houses the Center for Combat Use and Retraining of Personnel, the…