In the final episode of the series, Usha takes a closer look at the people behind the nuclear arms race. At the 1955 Geneva Summit, the superpowers tried to manage the dangers of the Cold War through face-to-face diplomacy, dealing with each other as people rather than as faceless nuclear arsenals. Yet Khrushchev's frosty reception of Eisenhower's Open Skies proposal showed just how far the two sides still had to go. Usha interviews several experts who stress that, decades later, empathy and respect are still critical -- and, right now, conspicuously absent -- elements of U.S.-Russia nuclear diplomacy. Meanwhile, in the secretive atomic communities built for plutonium production, the human toll of nuclear competition was becoming painfully clear. From Eisenhower and Khrushchev to factory workers in the atomic cities to morally conflicted scientists like Andrei Sakharov, every human being with a role in the nuclear Cold War had to wrestle with the physical and emotional costs, the moral dilemmas, and the irresolvable contradictions of this most terrible weapon.

Guests: Alexandra Bell, Dr. Anya Fink, Dr. Kate Brown, Dr. Olga Oliker

Once the Soviets got the nuclear arsenal Stalin had sought, they had to learn to live with the bomb - and all the dilemmas that came with it. This episode examines how the Soviet Union adjusted to the difficult new reality of being a nuclear power. Leaders like Khrushchev and Molotov struggled to resolve the contradictions of nuclear warfare, while the scientists felt burdened by the emotional impact of what they saw at the atomic test sites. Usha looks at how the Soviet military planned for nuclear war and tries to understand why the two sides continued to build up ever-bigger arsenals even after they had enough firepower to destroy the enemy several times over. For the Soviets, as for the Americans, living with the bomb was a never-ending struggle to prepare for nuclear war while trying to keep the nuclear peace.

Guests: Dr. David Holloway, Dr. Pavel Podvig, Dr. Olga Oliker 

What happens when a poor country, ravaged by war and brutalized by a totalitarian dictator, but dead-set on international greatness, tries to become a nuclear superpower? This episode - the first of three covering the Soviet nuclear program - explores how Josef Stalin, desperate to match American nuclear might after Hiroshima and Nagasaki, set his country on a path from which it would never turn back. Usha looks at the shadowy network of spies bringing atomic secrets into the Soviet Union, the rise and fall of the terrifying Stalinist henchman Lavrenty Beria, and the mysterious "atomic cities" where battle-hardened prison laborers helped produce nuclear fuel - when they weren't drinking and getting in fights. Four years after Hiroshima, Stalin's orders became a reality when the first Russian atomic test lit up the sky over the Kazakh steppe - and the nuclear arms race truly began.

Guests: Dr. David Holloway, Dr. Kate Brown