The Peloponnesian War: Pericles's Strategy Approved

In reading Thucydides’ account of the Peloponnesian War, modern observers often ask whether his praise of Pericles’ strategic plan was truly justified by the subsequent conduct of the war. On the one hand, Thucydides insists that Pericles foresaw how Athens could survive—or perhaps even prevail—despite numerous setbacks, including widespread devastation of Attica by the Spartans, the revolts of Athenian allies, and the catastrophic outbreak of plague. On the other, many scholars have questioned whether the so-called “Periclean strategy,” essentially defensive in spirit, was ever tenable in a struggle of such magnitude. How could Athens rely almost exclusively on fortifications, maritime raids, and economic resilience to force the Spartans into a permanent stalemate—or an eventual peace on terms favorable to Athens?

This post explores a fundamental point: Thucydides’ belief in the soundness of Pericles’ grand design arises from a deeper insight into Spartan capabilities. Pericles understood that the Spartans’ “conventional” strategy of invasion and ravaging was inherently limited and would not gain them decisive leverage if Athens retained her navy and financial strength. Thucydides perceived that the shortcomings of Spartan land-power—and the internal conflicts within Sparta over what sort of war to fight—proved the wisdom of Pericles’ approach. Even if Athens could not miraculously “conquer” Sparta with the same speed that Sparta ravaged Attica, a war of attrition would, in Pericles’ view, eventually compel the Peloponnesians to give up their dream of shattering the Athenian Empire.

Below, we will examine the core components of Pericles’ war plan, the Spartan strategies that opposed it, and the complex debates at Sparta between those who wished to “free the Greeks” by dismantling the Athenian empire at any cost and those who would rather negotiate a compromise peace. By the end, we will see why Thucydides, with all his meticulous narrative detail, concluded that Pericles had essentially been right from the start.

Pericles’ Strategy and Thucydides’ Endorsement

Thucydides lays out Pericles’ defensive-oriented plan most explicitly in Book I (1.143.3–144.1) and Book II (esp. 2.13.2), with a summation in 2.65.7. Pericles’ logic was simple:

1. Evacuate Attica: Recognizing that Sparta’s greatest strength was in heavy infantry, the Athenians were to refrain from pitched battles on land and allow the Spartans to ravage Attica almost at will. Rather than risk the annihilation of their hoplites in open battle, the population would shelter inside the long walls of Athens.
2. Rely on the Navy: Because Athens held naval supremacy, she could sustain her empire, protect seaborne trade and supplies, and harass Peloponnesian coasts from the sea. Athens could import grain and resources, offsetting Spartan devastation of farmland.
3. Leverage Financial Resources: Pericles drew attention to the substantial reserves in the Athenian treasury, supplemented by ongoing revenue from allied tribute. He hoped these funds could pay for maritime raids and support the city’s provisioning throughout a war that might last many years.

Thucydides, summarizing Pericles’ career after his death, insists (2.65.5–6) that once the war truly began, Pericles’ insistence on staying behind the walls and exploiting naval power was sound. By contrast, the measures introduced after Pericles’ death often led to risky ventures and political discord. Thucydides believed Athens’ ill-fated expeditions and internal quarrels proved that if only the city had adhered to the policy of patience and maritime strength, it would not have suffered such grievous losses.

Nevertheless, questions linger. Was such a purely “defensive” posture, with occasional maritime thrusts, likely to resolve a conflict of this magnitude? Could Athens truly have forced the Peloponnesians to abandon hope of victory purely through frustration? And was Athens’ financial underpinning, including large-scale expeditions in the first two years (431–430), truly sustainable over decades—especially once the plague ravaged the city’s population?

To resolve these doubts, Thucydides points us to Sparta’s position. He shows that Pericles’ original assumption—that Sparta’s apparent land-based superiority masked internal dilemmas—was accurate. In other words, had Athens stood firm, the Spartans’ inability to sustain an offensive might have doomed their war effort or led them to compromise on Athenian terms.

The Spartans’ “Conventional” Strategy of Devastation

At the outbreak of the Archidamian War (431–421 BC), Sparta adopted what many have called the “conventional” approach. Its hallmarks:

1. Annual Invasions of Attica: The Peloponnesians planned to inflict maximum economic and psychological damage by marching en masse into Attica each year. Thucydides notes that two-thirds of the Spartan forces, augmented by allied contingents, laid waste to farmland, vineyards, and property. The Spartans expected that these invasions would swiftly force the Athenians to submit or come out to fight a decisive land battle.
2. Push the Athenians into Negotiations: In 431 and especially in 430, Spartan forces ravaged Attica again, expecting that the Athenians—suffering from devastation in the countryside—would cave in. Indeed, Thucydides indicates that in 430, an Athenian appeal for peace was made (2.59.2). This was a moment often overlooked: many Athenians, distressed by the plague and repeated ruin, were willing to treat with Sparta. To Peloponnesian eyes, it must have seemed their method of invasion was working.

However, from Thucydides’ vantage, the Spartans were overestimating how quickly such ravaging would compel total surrender. Although it did prompt the city to send envoys, Athens ultimately did not accept the extreme terms that would dissolve its empire. The Spartans had no intention of letting Athens off with mild conditions, since in 431 they believed they could “destroy the Athenians.” Overconfidence marked those initial years.

By 425, with repeated invasions and no conclusive breakthrough, Spartan leaders retained faith in the same approach—but faced a radical change of events at Pylos. That fiasco, which ended with Spartan hoplites captured on Sphacteria, fatally undermined the “conventional” strategy. Sparta, suddenly vulnerable, was forced to consider more drastic expedients.

The Rise of the “Adventurous” Strategy

Alongside annual invasions, there was another line of thought at Sparta—what might be called the “adventurous” or “innovative” strategy. It entailed a range of actions that diverged from the predictable approach of ravaging Attica:

1. Fomenting Revolts Among Athenian Allies: As early as 432, the Corinthians spoke in the Spartan assembly about enticing Athens’ maritime allies to rebel. Corinth explicitly suggested that the most effective method to undermine Athenian power was to deprive them of the revenue on which their fleet depended (1.122.1).
2. Seeking Persian Aid: From the start of the war, certain Spartans floated the idea of gaining support from the King of Persia—particularly financial backing that might pay for a new Peloponnesian fleet large enough to rival or even outnumber Athens’. Thucydides (2.7.2) mentions how Sparta hoped to build up to 500 ships with Persian help—an enormous figure in the Greek world at the time.
3. Naval Raids and Special Expeditions: In 429, a Spartan commander, Cnemus, tried to assemble a fleet that might challenge Athenian naval control near the Corinthian Gulf (2.85–92). Though ultimately defeated by the Athenian admiral Phormio, it reflected the Spartans’ willingness to experiment. Other minor attempts—e.g., a surprise attack on the Piraeus—were floated. Later, the Spartans established the colony at Heraclea in Trachis (426/425), which they hoped would serve as a base threatening Euboea (3.92.4).

Despite these ideas, the Spartans never fully committed to the “adventurous” path in the early Archidamian War. Their forays into naval campaigns were tentative. They lacked both a large fleet and the will to risk large numbers of full Spartan citizens overseas, especially as the essence of Spartan society demanded that Spartiates remain at home in control of the helots. The outcome was often half-measures: help from Persian envoys never fully materialized, and allied contributions to a major fleet were smaller than anticipated. Nonetheless, after the disaster at Pylos in 425, with Spartan prisoners held in Athens, Sparta moved decisively toward more “adventurous” methods—most notably harnessing helot manpower for extended campaigns and sending out the gifted general Brasidas to foment revolt among Athenian allies.

Brasidas’ Northern Campaign

When the Spartans realized that the old invasions had run aground politically—especially once Pylos fell—they embraced a new measure: sending helots abroad to fight under Brasidas. This was a landmark decision, given the Spartans’ historical fears of a helot uprising at home. Brasidas, an exceptionally energetic commander, now marched north to the Thraceward region around 424/423 to attack Athenian dependencies, notably Amphipolis. This expedition epitomized the “adventurous” strategy: systematically liberating allied cities from Athenian rule. Brasidas also insisted that his mission was precisely what Sparta had promised at the war’s outset—“to fight the Athenians for the freedom of the Hellenes” (4.86). This theme had special resonance: in 431, Sparta proclaimed itself the liberator of Greece from Athenian hegemony, but had done little to follow through until now.

Yet even in this “liberation campaign,” Sparta was hardly united. Brasidas repeatedly requested reinforcements after capturing Amphipolis (4.108). But the party at Sparta that wanted peace—keen to recover the hostages captured at Sphacteria—preferred negotiations and delayed sending him significant help. Diplomacy prevailed in 421 with the Peace of Nicias, an outcome that effectively undercut Brasidas’ plan of a broad anti-Athenian revolt. The Peace restored the prewar status quo in many respects, leaving the “cause of liberating Hellas” in limbo.

For Thucydides, Brasidas’ boldness highlights that Sparta was capable of more potent policies but lacked the determination to unify behind them. Spartan reluctance to support full-scale maritime or distant land campaigns preserved Athens from the worst damage. Meanwhile, the partial revolts that did occur ultimately failed in the face of Athens’ continuing naval power.

Political Divisions at Sparta

Behind these divergent strategic inclinations lay a deeper political divide—one that arguably dated back to the end of the Persian Wars. Sparta had once commanded the alliance against Persia, but withdrew in the 470s/460s when it realized a maritime empire demanded far-flung expeditions and large naval forces. Some Spartans still dreamed of restoring their old hegemonic primacy in all Greece; others resigned themselves to seeing Athens play that role, provided Laconia itself remained safe.

During the First Peloponnesian War (460s–446), these dilemmas bubbled up. Sparta secretly promised to invade Attica to help Thasos in its revolt (1.101.2), but soon after invited Athenian help against helot rebels at Ithome, only to dismiss them ignominiously—triggering long-term animosity. Later, in 446, when King Plistoanax withdrew from Attica and accepted the Thirty Years Peace, he was accused by other Spartans of having been bribed. The treaty left Athens’ empire largely intact, angering any Spartan who still cherished the dream of dismantling it altogether. Thus, on the eve of the Archidamian War, Spartan leadership was pulled in two directions:

1. Complete Liberation of Greece: This faction wanted to force Athens to dissolve its empire, seeking allies near and far, including Persia, to wage a “just war” to free Greek states from Athenian rule.
2. A Negotiated Settlement: Others, confronted with the reality of Spartan limitations, ultimately preferred to do a deal—accepting Athens’ empire in some form so long as Spartan territory was safe and the city’s immediate allies were protected.

In 431, the official line was to “free the Greeks” or, in Thucydides’ phrasing, “destroy the Athenians” (4.85.2). But as soon as major setbacks occurred, such as the Pylos affair in 425 or a renewed stalemate in 421, Spartans would abandon this rhetoric, seeking compromise. Thucydides argues that Pericles understood precisely this tension. By avoiding ruinous land battles, Athens effectively forced Sparta either to attempt a more radical maritime approach (which was beyond its capacity) or to admit they could not break the Athenian empire by ravaging farmland alone.

The Peace Overtures of 425: A Moment of Spartan Contradiction

One of the most revealing episodes occurs in 425, when Spartan envoys appealed to Athens for peace after the loss of Spartan hoplites on Sphacteria. They wanted those men back—some of them full Spartans from elite families—and were willing to contemplate a settlement that recognized a significantly intact Athenian empire. Such a policy contradicted every boast Sparta had made about “freeing the Greeks.” The final entreaty of these ambassadors was that Athens and Sparta, if allied, could dominate the rest of the Greek world. Yet, as Thucydides emphasizes, it was a betrayal of Sparta’s long-standing claims to champion Greek freedom (4.20–22). They dared not speak candidly in front of the Athenian popular assembly, since Spartan allies in the Peloponnese would be outraged to learn Sparta was ready to cut a deal behind their backs.

The Athenian rejection of these peace overtures, driven by Cleon and an electorate confident in the leverage gained at Pylos, forced the Spartans to think anew about a more “adventurous” path. Brasidas’ campaign in Thrace emerged after 425 as the manifestation of those Spartans who were still committed to dismantling Athens entirely. Once again, Sparta was divided between making a moderate deal and pursuing total victory. The moderate side wanted the hostages returned to end the war; the “adventurers” (Brasidas especially) wanted to keep pushing. That tension never fully resolved, and the Peace of Nicias in 421 left many Spartans dissatisfied.

The Larger Arc: From Archidamus to Lysander

Throughout the entire conflict, from Archidamus in the early Archidamian War to Lysander and Callicratidas in the final Ionian phase, one sees repeated evidence of the same divide:

• Archidamus: Cautioned caution and advocated preparing to build a fleet, ally with Persia, or exploit other indirect means. His logic was strategic, but also seemingly reluctant to rush to war that would require deeper transformations of Spartan society.
• Brasidas: With bold maritime/land expeditions far from home, he incarnated the radical “let us indeed free the Greeks” approach, in effect championing the cause that had been so central to Sparta’s justification for war.
• Callicratidas: Famously scorned the humiliating reliance on Persian subsidies, remarking that Greeks were “wretched” to beg money from barbarians (Xen. Hell. 1.6.7). He openly proposed reconciling with Athens. The radical stance “free all Greeks from Athenian rule” required Spartan subservience to Persia—an irony unacceptable to him.
• Lysander: Went the other way, cooperating closely with the Persian prince Cyrus, accepting large sums of money to pay rowers and build up a fleet that could decisively defeat Athens at sea. This was indeed the final “adventurous” strategy that ended in Athens’ capitulation in 404 BC. Without Persian gold, the Spartans never could have achieved so thorough a victory.

At each stage, a more moderate wing stood ready to broker peace, effectively leaving Athens in possession of much of its empire. And at each stage, some Spartans (like Brasidas and later Lysander) believed that for Sparta to accept a partial victory was to betray the initial proclamation. For Thucydides, the key point is that until the arrival of Persian gold in the Ionian War, Sparta had no sure path to total victory. The “adventurous” strategy, in principle, could unravel the Athenian empire only if heavily subsidized by an external power. Athens, if left largely intact, would remain potent at sea.

This fact resonates with Thucydides’ view of Pericles’ defensive approach. Sparta could not break Athens quickly by ravaging farmland, nor easily replicate the massive naval resources that underpinned Athenian power. Hence Pericles, if not for the plague and subsequent misjudgments by his successors, might have seen Athens hold on until Spartan efforts collapsed or triggered a moderate peace that recognized the Athenian status quo.

Thucydides’ Verdict on Periclean Strategy

Given this context, why did Thucydides so emphatically side with Pericles—declaring that if the Athenians had adhered to his plan, they would not have lost the war (2.65.7)? Four key reasons emerge:

1. Spartan Weakness at Sea: Thucydides recognized that Sparta lacked a true maritime tradition and would struggle to challenge Athenian naval supremacy. Although Spartans flirted with building or borrowing fleets, these efforts never gained traction until Persian subsidies poured in after 412 BC. Pericles’ emphasis on preserving Athens’ navy and finances was therefore wise.
2. Financial Endurance: Pericles believed Athens had the capital and the imperial revenues to weather a drawn-out conflict. Thucydides repeatedly underscores Athens’ advantage in money and ships. While the war was costly, the city’s initial financial reserves (with the allied tribute) made a multi-year strategy viable—so long as Athens did not undertake ruinous extra ventures.
3. Spartan Political Divisions: The repeated vacillations at Sparta, from invasive ravaging to half-hearted attempts at naval warfare, strongly indicated that they could not unify around a single plan. Some Spartans sought to end the empire fully, while others sought compromise. That made them slow to adopt bold moves or sustain complex campaigns.
4. Athenian Missteps After Pericles’ Death: Thucydides portrays how, with Pericles gone, Athens veered into questionable adventures (the Sicilian Expedition, internal political feuds, and so forth). The plague that broke out early in the war certainly undermined morale and manpower, but the fiasco in Sicily was a voluntary choice that fatally weakened Athens and gave Sparta renewed hope—particularly once Persian aid became a factor.

Thus, while some modern readers might find it hard to accept that “sitting behind the walls” could achieve a true “victory,” Thucydides believed victory to be relative. By denying Sparta any quick path to success and by controlling the seas, Athens might have forced the Spartans into a negotiated settlement that preserved the empire’s core. That result, in Thucydides’ eyes, would have validated Pericles’ original stance.

Two Frequent Objections: Financial Feasibility and Offensive Raiding

Many scholars have asked two major questions about Pericles’ approach:

1. Financial Feasibility: Could Athens fund frequent naval expeditions, pay crews, and maintain an influx of imported supplies indefinitely? After all, Pericles himself once called “forced contributions” (φόροι collected under pressure) a suboptimal way to finance war (1.141.4). Thucydides’ narrative suggests the city was under acute strain by 430, and the plague further complicated matters. But even with these challenges, Pericles argued Athens still had enough raw capital and maritime reach to see the conflict through. Thucydides, focusing on the short initial phase (431–429), felt that the plague was an exceptional blow, not an inevitable financial meltdown of the strategy.
2. Why No Major Offensive?: It can seem unrealistic that Athens could end such a conflict merely by being defensive. In practice, Pericles did plan maritime raids against Peloponnesian coasts—an “offensive at sea” meant ravaging Epidaurus, Troezen, and other Spartan allies. These campaigns, though they did not match the grand scale of the Spartans’ land invasions, showcased how Athens could retaliate. Thucydides saw no contradiction: for a city whose strength lay in seapower, a maritime “offense” was more akin to strategic raiding than large-scale conquests.

Additionally, the war could have ended with a negotiated compromise that fell short of a crushing Spartan defeat—but still preserved Athens’ autonomy and much of its alliance network. Indeed, the Spartans showed repeated willingness to make a deal if they felt the tide was turning. Thucydides thus concludes that only the plague and subsequent policy blunders prevented Pericles’ vision from bearing fruit.

Afterthoughts: Could Athens Still Have Failed?

One must concede that no strategy can guarantee absolute triumph in a multi-decade war. If Athens had continued to adhere strictly to Pericles’ approach, might it still have collapsed from exhaustion, plague, or unforeseen disruptions in food supply? Possibly. But Thucydides’ overarching argument is that Spartan weaknesses ran deeper than many realize:

• Short “Burning” Campaigns: Ravaging Attica seasonally was psychologically devastating but not fatal to a maritime state.
• Inability to Coordinate a Naval Program: Spartan attempts to become a sea power floundered without external subsidy—money that only arrived in earnest after 412 BC from Persia.
• Internal Tension Over War Aims: Spartan leaders kept drifting toward half-measures or negotiated truces because they could not unify behind a single objective, i.e., total destruction or a partial settlement.

Pericles calculated that, in the absence of a major external factor (such as Persian gold), Sparta would eventually yield. Thucydides evidently found that reasoning persuasive in light of the repeated hints that Sparta would cut a deal whenever it failed to secure a swift submission from Athens.

Conclusion: Why Thucydides Was So Confident

Thucydides’ admiration of Pericles rests on the historian’s understanding of Spartan limitations and the city’s internal divisions. Pericles’ “testament” was simple: hold steady, leverage maritime supremacy, conserve financial and human resources, and wait for Spartan aggression to founder on its own structural weaknesses. That Athens deviated from this policy—and that plague and the Sicilian catastrophe intervened—only confirmed to Thucydides how wise Pericles’ original stance had been.

The Spartans, for their part, oscillated between the “conventional” annual invasions (431–425) and “adventurous” overseas expeditions that demanded more manpower and better naval skill. Only in the war’s final phase, with Lysander forging an alliance with Persian Prince Cyrus, did Sparta muster a sustained naval challenge capable of toppling Athenian control. By then, Pericles was long dead, and Athens had overextended itself in Sicily, losing crucial ships and soldiers.

Hence, Thucydides’ judgment of Periclean strategy is not about endorsing passivity. Rather, it underscores that Athens’ advantage was at sea and in money. If Athens avoided ephemeral land battles and suppressed the temptation to overreach, then Spartan morale and alliances would sooner or later unravel. Thucydides viewed it as a tragic twist that Athens, after Pericles’ death, lurched away from this plan at critical junctures, ultimately paying a dreadful price.

This analysis helps clarify why Thucydides lavishes so much space on the tensions within Sparta, the repeated unfulfilled talk of naval building, and the persistence of Spartan factional struggles over how far to go in fulfilling the boast of “liberating the Greeks.” By weaving these elements together, Thucydides shows that Pericles, the seasoned statesman and strategist, rightly predicted that all Sparta’s zeal could not destroy Athens—unless Athens foolishly played into Spartan hands or an unanticipated foreign power intervened. That is exactly what happened, and it vindicated Thucydides’ belief in Pericles’ foresight.

In the end, the question “Was Thucydides right?” is answered best by observing how the Peloponnesians ultimately won: not through the classic “conventional” strategy but via new financial streams from Persia, and a naval revolution that Pericles had never expected them to be capable of. Thucydides leaves readers with a bittersweet sense that Athens possessed a sound plan from the beginning—only to see it undermined by war weariness, disease, and strategic recklessness in later years. Pericles’ strategy, as Thucydides understood it, was not about achieving a single, crushing blow against Sparta; it was about preventing Sparta from doing so against Athens and forcing them, eventually, to a non-catastrophic peace. For Thucydides, this vision was both perceptive and tragically unrealized.