President Obama defended the Iran deal at American University in Washington this week, inviting comparisons to President Kennedy’s address there in 1963. While some consider the allusion a masterstroke of political theater, the JFK comparison might not suit the president as well as he thinks.

Kennedy spoke at American to defend the Partial Test-Ban Treaty he had been forging with the Soviet Union. Just eight months after he had stared down the Soviets during the Cuban Missile Crisis, Kennedy was negotiating from a position of strength.