Everything inside 'nuclear football' that Donald Trump keeps by his side everywhere he goes

Like in the movies, the President of the United States actually carries around a briefcase everywhere in the event of a nuclear war.

OK, I lied. Donald Trump doesn't physically carry around the ‘nuclear football’. That's the job of a military aide who stays nearby the president at all times.

But whether the 78-year-old is in Washington, Air Force One, or about to deliver a shocking message about US tariffs, he's got it in close proximity.

Known as the 'president's emergency satchel', yet commonly referred to as the nuclear football, the public first found out about it after a photo of the suitcase was taken at the Kennedy Family Compound in Massachusetts in May 1963.

The nickname was reportedly given by White House aide Jack Valenti in a 1965 newspaper article, possibly in relation to the Kennedy family's love of touch football.

What’s inside Donald Trump’s ‘nuclear football’?

Although Trump doesn't actually have a 'nuclear button', as such, the case happens to contain communication tools, authentication codes and a book with several pre-set nuclear strike options.

So the 'biscuit' is what the active president needs to use to order a nuclear strike.

It is separate from the football and isn't actually a biscuit, in any way, shape of form.

I'm sure he keeps a cheeky snack draw in the Oval Office for that.

Donald Trump's 'nuclear football' is also known as the 'president's emergency satchel' (BRYAN DOZIER/Middle East Images/AFP via Getty Images)

The biscuit is a physical card containing codes which are needed to identify himself to the military.

"When they explain what it represents, and the kind of destruction that you're talking about, it is a very sobering moment," Trump told ABC during his first term.

"It's very, very scary, in a sense."

Once Trump has identified himself, he passes his order to the highest-ranking US military officer, the Chairman of the Joint Chiefs of Staff.

As reported by the BBC, the order is then sent to the US Strategic Command HQ in Offutt Airbase, Nebraska.

The codes given by the president will need to match the same codes that are in the launch team's safes. Apparently, the president's order cannot be disobeyed.

Following Trump's inauguration in January, Senator Edward J Markey and Congressman Ted Lieu said: "As Donald Trump returns to the White House, it is more important than ever to take the power to start a nuclear war out of the hands of a single individual and ensure that Congress’ constitutional role is respected and fulfilled.

"We must put guardrails on presidential authority to start nuclear war. We must never again entrust the fate of the world to just one fallible human."

What would happen if there was a nuclear attack?

The threat of nuclear war is always there (Getty Stock Images)

Roughly five billion people would die within 72 hours of a nuclear strike, according to the author of Nuclear War: A Scenario.

Annie Jacobsen told The Diary of a CEO podcast that the two safest places to live would be New Zealand and Australia - both of which are pretty isolated from the rest of the world.

On what would actually happen in the event of a nuclear war, however, she explained: "I describe the first bomb in the scenario that strikes the Pentagon, it's a one megaton thermonuclear bomb in painstaking, horrific detail, all sourced from Defence Department documents, defence scientists who have worked for decades to describe precisely what happens to things and to humans.

"And it's horrifying, but on top of the initial flash of thermonuclear light, which is 180 million degrees, which catches everything on fire in a nine mile diameter radius, on top of the bulldozing effect of the wind and all the buildings coming down, and more fires igniting more fires, on top of the radiation poisoning people to death in minutes and hours and days and weeks, if they happen to have survived.

"On top of all that, each one of these fires creates a mega fire that is 100 or more square miles."