It's not hard to imagine a world where at any given moment,

you and everyone you know could be wiped out without warning

at the push of a button.

This was the reality for millions of people during the 45-year period

after World War II,

now known as the Cold War.

As the United States and Soviet Union faced off across the globe,

each knew that the other had nuclear weapons capable of destroying it.

And destruction never loomed closer than during the 13 days

of the Cuban Missile Crisis.

In 1961, the U.S. unsuccessfully tried to overthrow Cuba's new communist government.

That failed attempt was known as the Bay of Pigs,

and it convinced Cuba to seek help from the U.S.S.R.

Soviet premier Nikita Khrushchev was happy to comply

by secretly deploying nuclear missiles to Cuba,

not only to protect the island,

but to counteract the threat from U.S. missiles in Italy and Turkey.

By the time U.S. intelligence discovered the plan,

the materials to create the missiles were already in place.

At an emergency meeting on October 16, 1962,

military advisors urged an airstrike on missile sites

and invasion of the island.

But President John F. Kennedy chose a more careful approach.

On October 22, he announced that the the U.S. Navy

would intercept all shipments to Cuba.

There was just one problem:

a naval blockade was considered an act of war.

Although the President called it a quarantine

that did not block basic necessities,

the Soviets didn't appreciate the distinction.

In an outraged letter to Kennedy,

Khrushchev wrote, "The violation of freedom to use international waters

and international airspace is an act of aggression

which pushes mankind toward the abyss of world nuclear missile war."

Thus ensued the most intense six days of the Cold War.

While the U.S. demanded the removal of the missiles,

Cuba and the U.S.S.R insisted they were only defensive.

And as the weapons continued to be armed,

the U.S. prepared for a possible invasion.

On October 27, a spy plane piloted by Major Rudolph Anderson

was shot down by a Soviet missile.

The same day, a nuclear-armed Soviet submarine was hit by a small-depth charge

from a U.S. Navy vessel trying to signal it to come up.

The commanders on the sub, too deep to communicate with the surface,

thought war had begun and prepared to launch a nuclear torpedo.

That decision had to be made unanimously by three officers.

The captain and political officer both authorized the launch,

but Vasili Arkhipov, second in command, refused.

His decision saved the day and perhaps the world.

But the crisis wasn't over.

For the first time in history,

the U.S. Military set itself to DEFCON 2,

the defense readiness one step away from nuclear war.

With hundreds of nuclear missiles ready to launch,

the metaphorical Doomsday Clock stood at one minute to midnight.

But diplomacy carried on.

In Washington, D.C., Attorney General Robert Kennedy

secretly met with Soviet Ambassador Anatoly Dobrynin.

After intense negotiation, they reached the following proposal.

The U.S. would remove their missiles from Turkey and Italy

and promise to never invade Cuba

in exchange for the Soviet withdrawal from Cuba under U.N. inspection.

Once the meeting had concluded,

Dobrynin cabled Moscow saying time is of the essence

and we shouldn't miss the chance.

And at 9 a.m. the next day,

a message arrived from Khrushchev

announcing the Soviet missiles would be removed from Cuba.

The crisis was now over.

While criticized at the time by their respective governments

for bargaining with the enemy,

contemporary historical analysis shows great admiration

for Kennedy's and Khrushchev's ability to diplomatically solve the crisis.

But the disturbing lesson was that a slight communication error,

or split-second decision by a commander, could have thwarted all their efforts,

as it nearly did if not for Vasili Arkhipov's courageous choice.

The Cuban Missile Crisis revealed just how fragile human politics are

compared to the terrifying power they can unleash.