Shortly after World War II, the prominent British diplomat and historian Alfred Zimmern lauded America for what it had in common with the ancient republic of Athens. “The important respect in which the two peoples resemble one another is their astounding vigor and freshness of mind,” Zimmern declared in a 1947 article for the Classical Journal. Today, the analogies are not so generous: the senior Kenyan official Macharia Kamau declared last year that the United States “behaves as if it is a 21st Century ancient Athens . . . arrogant, discriminatory, powerful, declining and in denial.” In his 2009 book From Democrats to Kings, the British classicist Michael Scott cautioned that ancient Athens, a “waning star on the international stage resting on past imperial glories,” should be a warning to the West.

Though today Americans are more apt to compare themselves to Rome, there are some significant similarities between our own situation and that of ancient Athens, as is evident from the historian Paul A. Rahe’s new book, Sparta’s Third Attic War: The Grand Strategy of Classical Sparta, 413–404 BC. The comparatively prudential foreign policy decisions of Sparta, Athens’s preeminent competitor in ancient Greece, offer an alternative approach that American leaders would do well to consider.

Following the Greeks’ impressive defeat of the Persians at the battles of Salamis (480 BC) and Plataea (479 BC), the great city-state of Athens sought to capitalize on this momentum against the greatest empire in the Mediterranean world through a series of conflicts known as the Wars of the Delian League. One of these military campaigns was an invasion of Egypt in 460 BC in support of a rebellion encouraged by a Libyan king living on Egypt’s border. The Athenian-led Delian League sent a fleet of perhaps as many as two hundred ships to support the revolt, which in time turned into a six-year conflict between the Greeks and Persians. Historians estimate that total Athenian casualties during the far-flung expedition may have totaled as many as fifty thousand men and 250 ships, a huge percentage of their able-bodied men and navy.

The Egyptian campaign was a disaster for Athens, one that might have convinced its leaders of the limits of their city-state’s power. Though the Athenians had a strong navy, they seemed unable to project their power far from their base in the Aegean. Nor did they ever have an especially dominant army—it was the legendary Spartan Three Hundred, after all, who fought off thousands of Persians at Thermopylae. While the renowned center of culture and learning was capable of defending its own neighborhood, distant conflicts were beyond its capacity. Nevertheless, forty-five years later Athens would attempt a very similar military expedition in Sicily. It would be that catastrophe, so demonstrably tangential to their struggle with their primary Greek adversaries, the Spartans, that would break the back of that once-great Greek city-state.

As the title suggests, Rahe’s text foregrounds Sparta, also known as Lacedaemon, in order to reveal new trends and insights regarding ancient Greece. In an interview last year, Rahe noted that modern historians tend to present Athens and Sparta as diametrically opposed entities, the former an enlightened progenitor of modern democracy and science and the latter a grim, militarized, oligarchic society. Yet, he argues, these two societies, whatever their differences, had far more in common with each other than they do with us moderns: neither society was built on commerce, and both depended on large slave populations to sustain their way of life.

Although Athens was a democracy, it was constantly at war, while the oligarchic Sparta was extremely cautious, a state always preparing for war but rarely engaging in it. This was largely because of the incredible imbalance between free citizens and state-owned serfs, known as helots (helots outnumbered free citizens by perhaps as much as seven to one, according to Herodotus). Meden agan, translated “nothing too much,” was the prudential motto of Sparta, which positioned itself as a defender of local autonomy.

Sparta was far more skilled at diplomacy than was the often-impetuous Athens (another consequence of the former’s governing such a large percentage of unruly serfs). Ill-suited for domination over the Aegean, Sparta opted for a grand strategy that was a form of isolationism, often relying on proxies. Ironically, those proxies indirectly included Athens itself: Sparta needed its rival and its navy to ward off the threat of the Persian Achaemenid Empire, but neither could it countenance an Athens strong enough to threaten its hegemony within the Peloponnese. Lacedaemon thus pursued what Rahe calls a “necessary imperialism” in its immediate backyard, mostly to counter the encroachment of Athens.

That strategy of caution paid off when compared to the reckless and increasingly politically unstable Athens, which, after the brilliant leadership of Pericles (who died in 429 BC) pursued a number of foreign policy objectives not germane to their immediate strategic needs of preserving their dominance over a number of client city-states in the Aegean. And nothing was more poorly calculated than its decision in 415 BC to send a military expedition to aid its ally Segesta on the island of Sicily in a vain attempt to counter Syracuse, the most powerful city-state on the island and a major competitor with Athens.

Things went badly from the beginning. The expedition’s leading advocate, Alcibiades, was recalled from command to stand trial in Athens before his fleet arrived in Sicily. Though the Athenian army had some early successes, Sparta’s entrance into the conflict soon turned the war in Syracuse’s favor, and the Athenians lost their first armada. Rather than accept that humiliation, Athens doubled down, sending a massive reinforcement armada, which was in turn defeated and destroyed in 413 BC. Most of the Athenian army was either killed or captured.

“Apart from greed and vainglory, the Athenians had no reason for their venture in Sicily,” Rahe argues. “Projecting power on such a scale at such a distance was exceedingly expensive, and it was a logistical nightmare. Moreover, even if they were victorious, it is by no means clear that they would have had resources sufficient for holding on to what they had won.” The Sicilian fiasco cost Athens somewhere between a fifth to a third of its already diminished adult male population, a loss that far exceeds anything suffered by a single people in the twentieth century as a consequence of war. The fact that Athens attempted this foolish venture even though its financial reserves were already exhausted from earlier crises and its population had suffered significant losses because of war and plague left the city in peril.

Military disaster after military disaster led to radical changes in the Athenian government, which worsened its political instability. Avaricious and ambitious Athenian leaders used lawfare to prosecute and blackmail the well-to-do. “They took a flawed but relatively stable political order—a kosmos in which one could hope that deliberative reason would for the most part hold sway—and they shattered it,” Rahe writes.

Sparta saw an opportunity in Athens’s discord and in 405 BC destroyed the Athenian navy at the Battle of Aegospotami, concocting a clever form of deception that resulted in the disabling of the Athenian government and military, which could no longer import grain or communicate with its empire. The Athenians were forced to capitulate and had to accept becoming yet another city-state within Sparta’s orbit.

“Battles are the principal milestones in secular history,” Rahe writes, quoting Churchill. It’s a hard claim to refute. The Athenians’ astonishing, come-from-behind victory over the Persians had propelled them to unparalleled prominence, and it was their foolhardy military adventurism in Egypt and Sicily that squandered that strategic capital and made them vulnerable to competitors such as Sparta. After Aegospotami, the Athenians were a dissipated power, subject to the whims of other nations.

“There is nothing known to grand strategists today that figures such as Thucydides and the statesmen he most admired had not already ascertained,” Rahe argues. Though demonstrating that hypothesis might require another multi-volume series, there’s no doubt that the story of Athens and Sparta remains instructive. Athens overestimated its own military capabilities and, in a half-century of far-flung campaigns, frittered away its many advantages over its adversaries. Obsessed with foreign policy adventurism, Athenian leaders failed to safeguard the property and livelihoods of their city’s farming population, and in time paid a heavy price for their recklessness.

As a new administration prepares to take the reins of office in Washington, the United States faces not identical, but perhaps analogous circumstances. After spending incredible financial resources and enduring tens of thousands of casualties in Iraq and Afghanistan—with embarrassingly little to show for it—have our foreign policy elites learned anything from their costly miscalculations? Or, with the prospect of “regime change” and “democracy-building” in the Middle East and Eastern Europe still tempting our internationalist establishment, will we continue to direct massive sums of money and materiel abroad, imperiling our own security interests in the process? Our enemies eagerly await an answer to those questions. And those answers may well determine whether our future more closely resembles the Athens or the Sparta of the fifth century BC.