The two Presidential flying command posts held at constant readiness in Australia for the duration of Barack Obama’s visit are more than exceptionally modified Boeing 747-200 Classic model jumbo jets, or the occasional specially equipped 757 or 767 in support.

These are, at worst, the Armageddon jumbo jets,  flying high or low over a world ruined by a nuclear holocaust, winding their way between the stratospheric funeral pyres of incinerated cities.  Either of them is ready to preserve the primary chain of command of the Union even if America has, to all intents and purposes, ceased to exist.

If that seems horrifyingly bleak, it reflects the thinking of the era in which increasingly elaborate Presidential jets were incorporated into the battle planning for nuclear conflict, or more likely, last minute nuclear brinksmanship.

One of these 747s , with its hog’s back of antennas and blisters and hatches that may be part of its anti-missile or anti-laser defences, becomes designated as Air Force 1 the moment it’s boarded by the President.

This is true of any aircraft the President boards, even a civilian airliner the President might use, except for several highly modified helicopters, which adopt the designation of Marine 1, as would other Marine Corps aircraft, typically within the US.

And Air Force 1 is not always the call sign. When President George W Bush left  Sarasota Airport in Florida soon after the 9/11 terror attacks on the Twin Towers and the Pentagon and remained aloft for many hours while the ‘situation’ was assessed and all other flights were grounded, his airborne command post was reported as using the call sign Angel.

Those two identically equipped presidential 747-200s are the most publicly visible components of a meticulously assembled process for ensuring that the President, or on death, the Vice President, or on his or her death, the Speaker of the House, assume the high command and provide continuity of executive branch leadership when America is under attack.

There are many aircraft involved, a small constellation of dedicated satellites, and  volumes of constantly updated scenarios at hand, all to facilitate plans for not just the executive office schedules, but catastrophic disruptions.

Never mind the order of business that was set down for the 27 hours or so that President Obama has been in Canberra and Darwin or in transit.

In a sudden crisis Obama would be on board whichever jet is designated as fast as he could be helicoptered or driven to it by one of two duplicate presidential limos.

Either jet is in constant readiness to be the platform from which the President, as Commander in Chief, can wage war, including nuclear war in the nightmare worst case scenario of incoming missiles targeting him wherever he might be, or streaking toward multiple strikes on US cities, or its nuclear missile carrying submarines, or land based missile bases.

These jets are designed to fly indefinitely, so long as mid-air refueling is possible, and carry enough food to feed at least 100 people on each for up to ten days.

As such they represent planning for the nightmare of a limited or full nuclear exchange between east and west, even though, by the time they were put into service in 1990, what was the constant background fear of post war generations had begun to fade, and even the terrorism fears that reached fever pitch in the ‘70s, had receded, only to come screaming back on 9/11.

That is what you are really looking at when you see Air Force 1 on the TV today. Not what typically vanilla reports say about Air Force 1’s communications capabilities, or its operating theatre, or its hold full of support vehicles (although the really large ones travel in a separate military transporter).

What you are seeing is a flying command centre designed to cope with scenarios so terrible to contemplate that not even the attacks on the World Trade Center fully brought them back to life.

The ‘modern’ Air Force 1 wasn’t built to cope with al Qaeda, but a state armed with nuclear arsenals aimed at a US that had its own finger poised over similar triggers.

It might prove to be an irony that these two aged Presidential 747s having outlived that threat, are still around when new threats, real or concocted as they may be, are seen to be rising in China, India, Pakistan, Iran, North Korea and even a revitalized Russia.