Japan is set to become the fourth country to test-fly its own stealth jet — a move that is likely to increase its military presence in the region.

Air supremacy is crucial for today's combat and for national defense. Yet after Japan was defeated in World War II, its once superior aerospace industry, famous for the Zero fighter, has lagged behind the United States and other nations in development.

We look at what development of indigenous stealth jets, as well as Japan's homegrown fighters, means for Japan and the region.