When Pepsi or Coca-Cola comes out with a drink that the other competitor doesn't have.
Pepsi - Coca-Cola
Diet Pepsi - Diet Coke
Pepsi Vanilla - Vanilla Coke
Wild Cherry Pepsi - Cherry Coke
Pepsi Lime - Coke with Lime
Pepsi One - Coca-Cola Zero
There is no substitute for Coke, so there should not be another Cola War.