Historically, Russia’s defeat in foreign wars, including the Russo-Japanese War of 1904-05, World War I and the 1979-89 invasion of Afghanistan, has unleashed internal turmoil, ultimately leading to regime change.

Russian President Vladimir Putin’s unprovoked attack on Ukraine has stoked fears of a repeat, but this time with a nuclear threat far exceeding that posed by the collapse of the Soviet Union.

The prospect is chilling. If the Ukraine debacle destroys Putin’s domestic legitimacy, how should the United States (and the wider world) respond to the risk of “loose nukes,” or a vengeful leader going down with his finger on the nuclear button?