The scholars emphasized how close the Soviet Union and United States came to nuclear war during the Cuban missile crisis, as a result of several factors that so far aren’t at play today. Most noted the reassuring ways in which the Biden administration is aiming to avoid an escalatory confrontation with Russia. But they also stressed that escalation stemming from mistakes or miscalculation, which was the most salient source of danger during the Cuban missile crisis, poses a significant risk now as well.

And several cited troubling reasons—including how prolonged the current crisis is likely to be, and modern-day Russia’s weakness compared with the Soviet Union in every domain but nuclear-weapons power—for why the eruption of hostilities in Ukraine may have ushered the world into uncharted territory, limiting the utility of historical analogies and rendering the present moment potentially more precarious.

Certain dynamics that made the Cuban missile crisis so treacherous are, at this point, absent in the conflict over Ukraine. Whereas the 1962 incident was sparked by the U.S. discovery of Soviet efforts to deploy nuclear-capable ballistic missiles to Cuba, today Russia has not taken a comparable step to directly threaten vital American interests, such as relocating “nuclear missiles closer to the U.S. or West,” Mary Elise Sarotte, a professor at the Johns Hopkins School of Advanced International Studies, told me.