Simple logic indicates that only a Russian victory in Ukraine would prevent a nuclear world war, former Russian president Dmitry Medvedev said on Tuesday, addressing calls from the West that Moscow must not be allowed to win.

"Follow the simple formal logic," Medvedev argued on Telegram. "If Russia can't win, then apparently Ukraine must. Ukraine's war objective, as named by the Kiev regime, is the return of all territories previously belonging to it – that is, their separation from Russia."

This, Medvedev explained, would qualify as a threat to the territorial integrity of Russia and therefore "a direct reason for applying Clause 19" of the Russian state doctrine on nuclear deterrence – referring to the circumstances in which the use of atomic weapons by Moscow would be warranted.