The Strahl Republic (SDR) is the official National Defense Force of earth. At first, the SDR sent three foreign legion battalions and three armed police force battalions to the earth,  with regular troops arriving in 2882.

The SDR occupied New Canberra, the capital of the Earth's independent temporary government, and overwhelmed the mercenary army in various parts of the world, but the situation changed completely with the advent of AFS, and the SDR was caught in a quagmire war.