Russian President Vladimir Putin has putin-nuclear-threat.html">launched rhetoric about nuclear war in recent weeks, while escalating air missile attacks on Ukrainian cities after Russian forces suffered on-the-ground defeats. President Biden recently remarked that the world has only felt closer to nuclear war in 1962, at the height of the Cuban Missile Crisis. Though U.S. officials have stated they see no indication that Putin will follow through on his threats to use nuclear weapons, and Biden recently tempered his own response, the rhetoric has still left many on edge. We’re taking a look at what’s prompting Putin to escalate now and the rising stakes of Russia's war in Ukraine.

We're joined by Julian E. Zelizer, professor of history and public affairs in the Princeton School of Public & International Affairs and Nikolas Gvosdev, professor of national security affairs at the Naval War College and editor of "Orbis," a journal of world affairs by the Foreign Policy Research Institute.