Stirrups to Longbows
In most forms of conflict, adaptive responses to prior innovation usually determine the outcome.
Following up on the prior posting, here's a great summary of the Battle of Crecy, which determined the control of much of France in the late medieval period.
Illicit Networks, and Stirrups
Small innovations have great consequences in war, intelligence and civil societies.
A stabilized clock made possible the calculation of longitude, and shortly the British Navy sailed to its destinations, not the dead-reckoned vicinity of its destinations.
A gyroscope made possible the ability to fly a plane in cloud, to turn without whipping into a graveyard spiral -- and today we fly airplanes at Mach .80 as easily as we once rode the train or bus.