@JugglingWithEggs
Didn't Machiavelli write about divide and rule? And Sun Tzu who pointed out the art of war included not having one?
The Roman Empire played the tribes against each other, and their later politics is remembered as Byzantine. I rather think Chimpanzee troop leaders understand it on their scale.
Perfidious Albion may have formulated it as foreign policy, but that didn't cause the Medieval and early modern wars.