Kennedy took office at the height of the Cold War, a time of constant international peril and near-pervasive political anxiety that is very difficult to re-imagine today.
While JFK could rattle America's saber with the best of the cold warriors, his strong sense of detachment served him well. Kennedy kept his cool, maintaining a sense of proportion with an admirable singularity.
Little more than a minute into his inaugural, Kennedy reflected with chilling effect on mankind's ability to obliterate civilization on this planet. And, during his months in office, he exhibited the will and the courage to take the first steps away from Armageddon.
After the botched Cuban invasion known as the Bay of Pigs, which was planned on President Dwight Eisenhower's watch but given the green light by Kennedy, JFK viewed the advice that came from the State Department, Pentagon, and CIA with profound skepticism.
During the Cuban Missile Crisis, it was Kennedy who delicately and subtly led his advisors toward a path that averted what many feared would result in nuclear conflagration. And when the Soviet Union erected the Berlin Wall, Kennedy rightly saw Soviet weakness where others perceived provocation.
Kennedy's shining moment came when he delivered the commencement address at American University, five months before his death. There, with an eloquence that matched and may well have exceeded that of his inaugural, Kennedy set the stage for the first serious nuclear-arms-control treaty.
Kennedy paved the way for Richard Nixon's policy of détente with the Soviet Union and laid the foundations for the arms-control achievements of Ronald Reagan. In a clear and demonstrable way, Kennedy set the United States on the path, which, under President Barack Obama, will hopefully see the full adoption of the Comprehensive Test Ban Treaty.
Against considerable odds, Kennedy kept the nuclear peace in his time, thus making it possible for his successors to keep the nuclear peace in theirs.
By this supreme measure, Kennedy answered the call he issued in his historic inaugural address. Today, his legacy is society's challenge.
Video of Kennedy's major speeches, including his inaugural and American University address, is available at the website of the John F. Kennedy Presidential Library and Museum, jfklibrary.org. The library has mounted a special exhibition to commemorate the 50th anniversary of JFK's presidency. Comcast subscribers can view a collection of speeches, debates, campaign commercials, and other materials viacable.