Why do empires fall? Sometimes, it’s easy to identify a cause. Whether led by the Kaiser or by Hitler, Germany’s Second and Third Empires were destroyed by world wars. Germany’s ambition was simply too great, its militarism too dominant, its policies too harsh to win long-term converts, its leaders too blinded by the pursuit of power, its enemies too many to conquer or otherwise neutralize.

Other imperial falls are more complex. What caused Rome’s fall? (Leaving aside the eastern part of the empire, which persisted far longer as the Byzantine Empire.) Barbarians and their invasions, say some. The enervating message and spirit of Christianity, said the historian Edward Gibbon. Rome’s own corruption and tyranny, say others. Even lead in Roman water pipes has been suggested as a contributing cause to Rome’s decline and fall. Taking a longer view, some point to the rise of Islam in the 7th century and its rapid expansion into previously Roman territories as the event that administered the final coup de grâce to a dying empire.

America’s empire, it is clear, is now in decline, and a key reason is imperial overstretch as manifested by endless wars and overspending on the military (with literally trillions of dollars being thrown away on fruitless wars). An especially fine summary is Alfred McCoy’s article this week at TomDispatch.com. As McCoy notes:

In effect, the president and his team, distracted by visions of shimmering ships and shiny planes (with their predictable staggering future cost overruns), are ready to ditch the basics of global dominion: the relentless scientific research that has long been the cutting edge of U.S. military supremacy. And by expanding the Pentagon while slashing the State Department, Trump is also destabilizing that delicate duality of US power by skewing foreign policy ever more toward costly military solutions (that have proved anything but actual solutions) …

In just one extraordinary year, Trump has destabilized the delicate duality that has long been the foundation for US foreign policy: favoring war over diplomacy, the Pentagon over the State Department, and narrow national interest over international leadership. But in a globalizing world interconnected by trade, the Internet, and the rapid proliferation of nuclear-armed missiles, walls won’t work. There can be no Fortress America.

In this passage, McCoy stresses the damage being done by the Trump administration. But Trump is just the culmination of certain trends, e.g. favoring the Pentagon over the State Department is nothing new, as I wrote about here in 2010. And America has been in love with shimmering ships and shiny planes for generations, with several administrations supporting the F-35 jet fighter, a program that may end up costing as much as $1.4 trillion. Plenty of money for weapons that kill; not so much for medicines that cure: that’s imperial America in a nutshell.

I would stress that America’s strength overseas was (and is) always based on its strength at home in areas such as science, education, infrastructure, medicine, manufacturing, and exports. But what we’ve witnessed over the last 40 years is an immense and wasteful “investment” in wars and weapons even as our country itself has hollowed out. Science is now marked by the denial of facts (such as global warming). Education is all about students as consumers, with an overall decline in standards and performance. Infrastructure is crumbling. Medicine is too expensive and America’s overall health and life expectancy are both in decline. Manufacturing and exports have withered (except for the production and export of weapons, naturally).

As a result of all this, America is running a national debt of roughly 20 trillion dollars. The future is being sacrificed for the present, a tragic reality reflected in the latest Republican tax cut, which benefits the richest Americans the most, along with big corporations, and which will likely add another trillion to the national debt.

In short, America’s foreign decline is mirrored (and driven) by its domestic decline as reflected by its choices. Looking at the USA today, you get the sense it’s the best of times for the richest few, and the worst of times for so many Americans struggling with health care debt, student loan debt, and the uncertainty of low-wage jobs that could be outsourced at any moment. At the same time, the American political scene is driven by fear: of immigrants, of a nuclear war with North Korea, of Russian meddling (real or imagined), of growing Chinese power, and of the perpetually-hyped threat of terrorist attacks on “the Homeland.”

Empires can fall very quickly, as the “thousand-year” Third Reich did, or they can fall ever so slowly, as the Roman Empire did. But fall they do. What is in the cards for the United States? Readers, fire away in the comments section.

William J. Astore is a retired lieutenant colonel (USAF). He taught history for fifteen years at military and civilian schools and blogs at Bracing Views. He can be reached at wastore@pct.edu. Reprinted from Bracing Views with the author’s permission.