They are wrong to do so, and not only because this week's crisis is more the fruit of partisan gamesmanship in Washington than of Mr Trump's chaotic leadership. The shutdown is a sign of chronic dysfunction in American politics and society. Its roots are far deeper than the stalled negotiations between Republicans and Democrats over illegal immigrants, healthcare and fiscal policies that led to the latest funding freeze.

The extent of America's woes is apparent when it is contrasted with Australia's own imperfect political system. Just over 40 years ago, this country went through its greatest governance crisis when the Senate "blocked supply", refusing to allow the Whitlam government to spend. The prime minister was dismissed, as was his government when voters cast their judgment shortly afterwards.

That level of brinkmanship will likely not be seen again in Australian federal politics. The 1975 crisis led to today's solid consensus against blocking supply; bipartisan acceptance that an elected government must be allowed to govern.

In the four decades since Australia's sole, momentary "shutdown", US federal administrations have shut down 19 times. The reasons were widespread, and sometimes even trivial, ranging from serious differences over military spending to one side of politics simply wanting more time. Perennial battlefronts have included abortion laws and tax cuts for the rich.

A government shutdown should be regarded as a shameful failure of executive and parliamentary leadership. Yet in the US it has become a tactic. Services stop, public facilities and offices close, hundreds of thousands of public servants and soldiers go unpaid – and, somehow, this is acceptable.

Dysfunctional government, economic stagnation, military overreach and a fraying body politic are classic signs of unravelling empires. The US has all four.

Since the Cold War ended, its relative economic power has decreased and its citizens' median income has fallen. Its once-great strength, manufacturing, has been ceded to Asia and even Europe.

It is grappling with massive debt yet its leaders seem entirely unwilling to reduce it. Instead, the dominant Republicans push for further tax cuts in what is one of the lowest-taxing nations in the developed world. The party knows that tax perks for the mega-rich are unpopular, but it has little choice; it is beholden to donors who demand them.

Nor is it given that America will benefit from the world's next great economic leap forward; the Silicon Valley of the 21st century, whether that be in biotechnology, pharmaceuticals, alternative energy or another field. The US has for years been turning its back on the industries that may bring it prosperity, cutting spending on research and, more recently under Mr Trump, eliminating incentives for environmental protection and clean energy.

The President said on the weekend the shutdown was the Democrats' "nice present" to him on the first anniversary of his inauguration. In truth, it's not about him. The shutdown, like Mr Trump himself, is just another sign of an empire whose light is fading.