During the Seven Years' War (1756-1763) between Britain and France, George Washington was a young lieutenant colonel under his colonial master. His military experience with the British left a bad taste in his mouth, however. He was fed up with their arrogance and ignorance, which rivaled their French counterparts'. Indeed, he minced no words in criticizing the British for playing into the hands of the Native Indians allying with the French.
Learning from the Native Indians, Washington later proved to be good at wearing his British enemy down on an unending trail of hazards. Like the Native Indians, he was often able to pick his battles and battlefields. Unlike the Native Indians though, he never let the British divide and rule his fellow American revolutionaries.
In the American revolution (1775-1783), Washington's ragtag Continental Army appeared to be retreating most of the time. Meanwhile, the British army kept advancing, only to catch fever non-stop in the mosquito-infested South. Unlike the Southerners, British soldiers could hardly deal with malaria transmitted by Anopheles mosquitoes.* With too many sick and exhausted soldiers in tow, the British force simply couldn't fight any more. It surrendered to Washington in Yorktown, Virginia, on October 19, 1781. The war was practically over.
Accidentally the American revolutionaries weaponized malaria, to the detriment of their British enemy.