Former Russian president Dmitry Medvedev has once again threatened the West with an all-out nuclear war if Russia is pushed back to its 1991 borders. In a Telegram post on Sunday, the current deputy chairman of the Russian Security Council reiterated his well-known position that “nuclear powers never lose a war” as long as they defend their homeland. In a short thought experiment, he discussed the case of Ukraine’s success in this war. In his opinion, the return of Ukraine to its old borders would contradict the Russian constitution, especially as the conquered territories in eastern Ukraine a…