The shortest war in history lasted 38 minutes - Apparently.
On August 27, 1896, the British warship HMS Philomel fired a shot across the bow of the Chilean ship USS Blanco Encalada in the Strait of Magellan. The Chileans responded with a warning shot, and the British then apologized and withdrew. This brief skirmish, sparked by a dispute over Chilean neutrality, became the shortest war in recorded history. The conflict was so brief that it didn't even get its own official name, but it remains a strange footnote in the annals of military history.