Wars have been fought on myriad fronts throughout human history – on land, at sea, in the air, and even in the minds of strategists and commanders. 

But there’s one adversary that doesn’t wave a flag, doesn’t negotiate treaties, and doesn’t hold territory: disease. Time and again, this silent, invisible foe crept into the ranks of armies, influencing outcomes and altering the course of battles, campaigns, and entire wars.

Delousing machines, a piece of heavy artillery in the war against Typhus, Smallpox, and other diseases raging in the Balkans in 1919 (Wikimedia Commons)

The silent march of diseases – from dysentery to the Spanish flu – has often been relegated to mere footnotes. Yet, as any historian or military expert will attest, these illnesses played pivotal roles, constantly reshaping war strategies in ways unimaginable to generals and soldiers alike.

Join us as we look into this fascinating confluence of biology and battle. This piece uncovers how diseases have not only impacted but have often dictated the war strategies that shaped our world.

The Trojan Horse of Microbes: Surprise Attacks in History 

Historical records are replete with examples of armies that went into battle with a clear strategy, only to have those plans obliterated by an outbreak of disease. 

The Peloponnesian War, for instance, saw a mysterious plague devastate the Athenian population. This plague, often believed to be typhoid fever, shifted the balance of power and changed the trajectory of the war. 

Athenian war strategies were disrupted, not by the superior tactics of the Spartans, but by an unseen microbial foe.

From Trenches to Hospitals: The World Wars’ Invisible Front 

The World Wars introduced modern warfare techniques, mechanized divisions, and well-detailed war strategies. Yet, the old enemy – disease – remained.