US President Joe Biden has delivered a stark warning about Russian President Vladimir Putin's nuclear threats and said that the risk of atomic war had not been so high since the 1962 Cuban Missile Crisis and Putin's use of a nuclear weapon in Ukraine would end in Armageddon. US Studies Centre's Foreign Policy and Defence Research Fellow Tom Corben talked to ABC Radio National about how a leader doesn't generally use the word 'Armageddon' lightly despite President Biden's previous controversies in foreign policy matters.

He says, "US officials haven't downplayed the significance of Russia potentially using the nuclear weapons ... It is not just clear whether President Biden knows something we don't, about the potential movements Russian nuclear weapons to the battlefront in Ukraine or elsewhere."