It is disquieting to turn from these books about the early United States to one about our own century’s war in Afghanistan only to find some of the same flaws from the past, like the attempt to impose capitalist liberal democracy on people long accustomed to very different ways. Aaron B. O’Connell, the editor of OUR LATEST LONGEST WAR: Losing Hearts and Minds in Afghanistan (University of Chicago, $30), calls that country “the worst possible testing ground for a Western democratic experiment conducted at the point of a gun.”

The other contributors to the volume — almost all military veterans of the Afghan war — generally agree that the American people are culturally unable to win wars like this one. “Prudence was blinded by unexamined political and cultural assumptions, and the result was a massive and avoidable waste of time, lives and resources,” Aaron MacLean concludes; he led a Marine infantry platoon there and also holds a master’s degree from Oxford in medieval Arabic studies.

MacLean tellingly observes that the Americans were not trying to bring governance to a place that had none, but rather were trying to replace an existing unwritten constitution they didn’t understand and indeed barely perceived. “It consisted of traditional ethnic, tribal, state and religious patterns, all of which had been partially transformed by modernization and traumatically stressed by decades of war and the rise of Islamic radicalism,” he writes. Surprisingly, no good overview of our Afghan war has been published yet. Until that happens, this enlightening volume is probably the best introduction to what went wrong there, and why.

There is a common thread to almost all wars: They begin with hubris, stumble on miscalculation and end in sorrow. So it was, emphatically, with the Athenian empire’s invasion of distant Sicily in 415 B.C., during the Peloponnesian War. As a result of that poorly considered action, Athens eventually suffered political upheaval. “War abroad had given rise to civil discord at home,” Jennifer T. Roberts writes in THE PLAGUE OF WAR: Athens, Sparta, and the Struggle for Ancient Greece (Oxford University, $34.95). Reading that, I began to wonder if there was a parallel to the unnecessary American invasion of distant Iraq in 2003, and the election of Donald Trump to the presidency some 13 years later. Roberts, a classicist at the City University of New York, notes that as a result of its political turmoil, Athens found its democracy temporarily overthrown by an oligarchical “motley crew with differing goals.”

Do we really need another history of the Peloponnesian War? That was the question in my mind when I opened this book. When I finished it, I thought, yes, we seem to. Military historians often neglect developments in the arts, for instance, but Roberts weaves in Greek culture, showing how works by dramatists and philosophers reflected events in the war. Aristophanes’ “Lysistrata,” about women going on a sex strike to bring peace, was produced in 411 B.C., in the wake of the Athenian disaster in Sicily. She portrays the death of Socrates 12 years later as one more evil consequence of the war, with the great philosopher scapegoated “for the ills of a city that had suffered war, economic collapse, demographic devastation and civil strife.”

A less examined aspect of ancient history is the Praetorian Guard of the Roman emperors. Guy de la Bédoyère, a prolific British historian, tackles the subject in PRAETORIAN: The Rise and Fall of Rome’s Imperial Bodyguard (Yale University, $35). This is not an enjoyable book to read, but it is an interesting one, as the author pulls together the scraps and threads of information about the Guard. The problem is that so little is known about it that the story never really comes alive.

The Harvard historian David Armitage offers another unsettling echo from ancient history when he notes that the Latin phrase variously translated as “public enemy” or “enemy of the people” — the second used by President Trump to describe the American news media — was first devised by Romans in the context of their civil wars, as a way to justify violence against fellow citizens. But overall, his short CIVIL WARS: A History in Ideas (Knopf, $27.95) offers more dry analysis than juicy insights or rich narrative.