The Ancient Wisdom of Selective Sieges

Military history is replete with sieges—some glorious, some disastrous. Yet one of the most counterintuitive principles in classical Chinese strategy comes from Sun Tzu’s disciples: “Some cities should not be attacked.” This concept, articulated by Cao Cao and later commentators like Du Mu, reveals a sophisticated understanding of strategic priorities that still resonates today.

At its core, this philosophy argues that not all territory holds equal value. A small but heavily fortified city with ample supplies might drain an army’s resources while offering little strategic advantage. The true art of warfare, these strategists suggest, lies in distinguishing between targets that advance broader objectives versus those that merely satisfy tactical impulses.

Cao Cao’s Calculated Sacrifice

The warlord Cao Cao (155–220 AD), whose annotations on military classics became canonical, demonstrated this principle during his campaign against Xu Province. Facing two heavily defended minor cities—Hua and Fei—Cao made the unconventional decision to bypass them entirely.

Historical records show his reasoning:

– Hua and Fei were small but had formidable defenses
– Their garrisons possessed abundant grain stores
– Storming them would require disproportionate effort
– The provincial capital offered greater strategic value

By conserving his forces for the main objective, Cao Cao captured fourteen counties of Xu Province while leaving the stubborn outliers isolated. This mirrors Napoleon’s later maxim: “When you set out to take Vienna, take Vienna”—focus on decisive objectives rather than peripheral distractions.

The Rebel’s Dilemma: Speed vs. Siege

Nowhere does this principle carry greater consequence than in rebellions. Du Mu’s commentary highlights the existential stakes: successful revolts require lightning strikes at the enemy’s heart, not protracted sieges that allow regime forces to mobilize.

The 1519 Ning Rebellion exemplifies this. When Prince Ning revolted against the Ming Dynasty, his forces besieged Anqing—a gateway to Nanjing, the secondary capital. Military logic dictated pressing forward to claim Nanjing’s imperial legitimacy. Yet when philosopher-general Wang Yangming captured the rebel’s base at Nanchang, Prince Ning abandoned his nearly successful siege to retake his home territory.

Wang’s gamble succeeded spectacularly:

1. The prince diverted from his strategic objective
2. His army became trapped in Poyang Lake
3. The rebellion collapsed without reaching Nanjing

Contemporary advisors had pleaded with the prince using classic strategy: “Some cities should not be attacked. Sacrifice Nanchang, take Nanjing, and the empire follows.” His emotional attachment to his base proved fatal—a lesson for revolutionaries throughout history.

The Zhu Di Exception: When Boldness Wins

Interestingly, Prince Ning drew inspiration from his ancestor Zhu Di (the Yongle Emperor), who successfully rebelled in 1402. Zhu’s campaign initially followed conventional patterns—grinding battles across Hebei and Shandong that depleted his forces against the imperial army’s vast reserves.

The turning point came with intelligence revealing Nanjing’s weakened defenses. Zhu Di audaciously:

– Abandoned ongoing campaigns
– Marched directly south
– Secured the Yangtze through naval defections
– Entered Nanjing through opened gates

This mirrors Sherman’s Civil War “March to the Sea” or Patton’s WWII armored thrusts—bypassing strongpoints to strike at political and psychological centers. The Ming capital’s fall immediately transformed Zhu from rebel to emperor, proving that in rebellions, speed often outweighs territorial control.

Psychological Warfare: The Collapse of Morale

Du Mu’s commentary on Liu Song Dynasty rebel Shen Youzhi reveals another dimension: the fragile psychology of rebellion. When Shen’s 100,000-strong army bogged down besieging Yingcheng, his advisor warned:

“Rebellions thrive on momentum. If ordinary soldiers—many coerced into service—see early setbacks, their loyalty evaporates.”

Indeed, after failed assaults on Yingcheng’s formidable defenses:

– Troops began deserting en masse
– Shen’s aura of inevitability shattered
– The rebellion dissolved within weeks

This phenomenon reappears consistently—from Wat Tyler’s Peasants’ Revolt (1381) to modern insurgencies. Initial successes attract followers; early failures trigger collapse. Hence the strategic imperative to avoid demoralizing sieges when momentum matters most.

Modern Parallels: From Blitzkrieg to Network Warfare

Twentieth-century strategists rediscovered these principles independently. Heinz Guderian’s blitzkrieg doctrine emphasized:

– Bypassing strongpoints
– Penetrating to command centers
– Paralyzing enemy coordination

Similarly, John Boyd’s OODA loop theory prioritizes disrupting an opponent’s decision cycles over physical destruction. In cybersecurity, modern “strategic paralysis” targets data hubs rather than individual systems.

The throughline from ancient China is clear: whether facing Ming dynasty walls or computerized networks, strategic success often involves discerning what not to attack—conserving resources for decisive blows against an adversary’s will or capacity to resist.

The Enduring Lesson

Sun Tzu’s disciples grasped a profound truth: victory seldom requires total territorial control. By analyzing campaigns from Cao Cao to Zhu Di, from failed rebellions to modern warfare, we see that disciplined strategic omission—the art of leaving certain objectives untouched—often proves more valuable than compulsive conquest.

For leaders in any competitive arena, the challenge remains distinguishing between vanity objectives and truly decisive points. As the Ming rebels learned tragically, the city you refuse to attack may determine your fate as surely as the one you storm.