Ace Combat Zero: The Belkan War is the third and final PlayStation 2 game in the Ace Combat series, released in 2006. It acts as a prequel to the events of Ace Combat 5: The Unsung War, exploring "the war 15 years ago" referenced throughout the story. Zero retained the Wingman Command system from 5, and also introduced the Ace Style gauge, allowing players to shape their story depending on how they played.
Due to the PlayStation 3's launch in 2006, Ace Combat Zero did not sell as well as its predecessors; it was the first Ace Combat game to not hit 1 million sales. Despite this, it is still one of the most popular games in the series alongside the other PS2 games.