"On any given day we're about 34 minutes away from nuclear war."
That's the bone-chilling reality summed up by journalist and author Garret Graff, a nuclear security expert and historian who said many people don't realise the outdated system on which global nuclear security is based has no need for checks and balances.
"Whether you're talking about Air Force One or Marine One or the big hulking armoured motorcades, [they're] effectively tools to ensure that the President of the United States can launch a nuclear weapon from wherever he is at any given moment," he told news.com.au.
Despite Hollywood-style depictions of a nuclear football containing a big red button or retina scanner, the famed briefcase actually contains a "Denny's menu" of maps and weapons plans from which to order a hit.
If a strike is ordered, the President would take out "the biscuit" - a series of code words that identify him as the leader of the US and read them to the Pentagon who would confirm the launch.
The entire process would take just four minutes until the first missiles leave their silos and around 30 minutes until they landed anywhere in the world.
"There is no part of this process where there is a second voice that has to say 'yes there is a good reason to launch nuclear weapons'," Graff said about the system that requires a "two man" team to actually launch missiles themselves.
"Or 'yes, I've doubled checked and the President isn't crazy drunk right now.' The President at whatever state he is in at any moment only has to confirm that he is the President of the US. That is the only check or balance on the entire system. From there the entire system is geared towards launching nuclear weapons as fast as possible."
The "madman" theory
It's an issue brought into stark focus this week following Mr Trump's declaration at the UN general assembly the US would "totally destroy" North Korea if it threatened the country or allies.
"The United States is ready, willing and able, but hopefully this will not be necessary."
It comes amid a debate about whether the system should be updated to reflect modern geopolitical and technological realities.
In October last year, ten nuclear launch officers signed an open letter questioning Trump's experience and temperament when it comes to having his finger on the "proverbial red button."
Graff said the debate underscores the conundrum at the heart of nuclear deterrence - that each side needs to believe the other is crazy enough to use nuclear weapons but rational enough that they won't.
"It's impossible for outsiders to judge whether Kim Jong-un and Donald Trump are both playing entirely rational madmen or one or the other or both are actually mad enough to think that nuclear weapons could be a path out of this problem," he said.
"But the challenge with this system is it is entirely predicated on rational leadership and the ideal that the people who are in charge of those nuclear footballs either on our side or our adversaries ... understand that there is no such thing as a winnable nuclear war."
"So you need to have a situation where you on all sides believe that the leadership you're facing is intelligent and rational and that this entire system falls apart if you begin to doubt that."
Once a nuclear strike is ordered, Graff said the President would be evacuated within minutes to either an Airborn Command Centre or one of two permanent bunkers kept running for government officials in a doomsday scenario, at Raven Rock or Mount Weather.
Raven Rock is described as a "freestanding city" carved out of a hollowed out mountain near Camp David that would contain room for a post office, fire department, medical team, police and up to 5000 people.
Chilling plans initially laid out in the Cold War show the Post Office would be in charge of registering survivors while the National Parks would be set aside for refugee camps in the event of a nuclear strike.
Cash and "survival wafers" are said to have been stored with the Library of Congress having already determined the most valuable items they would take with them.
Graf said few would realise helicopters regularly flown over Washington are designed solely for that purpose, with the cost of keeping planes maintained and ready to go within minutes costs more than US$2 billion per year.
"These systems were set up for a different era and they are not technologically or geopolitically relevant to the modern day," he said.
"The question that we have as a society and as a civilisation is are we comfortable relying upon these outdated systems or do we need to modernise them to reflect what we actually face on a day-to-day basis?"