• The President of the United States has the sole authority to fire a nuclear weapon, but the steps are involved and complicated.
  • These critical steps work to safeguard against accidental launches and miscommunications.
  • Fifteen minutes after receiving the order, nuclear missiles could be ready to launch.
  • Watch the video above to see how the full process would work if the president called for a nuclear strike.

The following is a transcription of the animation.

It can take the US government just minutes to launch a nuclear weapon. Here’s how it would work.

The president has the sole authority to call for a nuclear strike. Once the call is made, a series of critical steps follow.

The president first meets with top military advisers. The meeting would take place in the Situation Room. If the president is traveling, a call is made on a secure line.

If the president still wants to go through with the strike, the order is verified. To authenticate the order, a challenge code is read to the president. It's usually two phonetic letters like "Delta-Echo."

The president then receives the "biscuit", a laminated card that's always near the president. The biscuit has the matching response to the challenge code.

The Pentagon then broadcasts an encoded message to missile crews. The message is only about the length of a standard tweet.

It includes the war plan, "Sealed Authentication System" or (SAS) codes, and the actual missile launch codes. When the launch crews get the message they open lock safes to obtain the SAS codes. These codes are compared with the SAS codes included in the message.

If fired from a submarine the captain, executive officer, and two others authenticate the launch order. Fifteen minutes after receiving the order, the missiles could be ready to launch.

If fired from land, there are 50 missiles controlled by 5 launch crews in different locations. Each crew "votes" for the launch by turning their keys at the same time.

There are five different keys, but only two need to be turned to launch the missiles. In this scenario, the missiles could be ready to launch just minutes after the president's order. Once the missiles are launched, there's no turning back.

EDITOR'S NOTE: This video was originally published on January 3, 2018. Lamar Salter contributed reporting on a previous version of this article.