Colonial Militias, Garrisons, and Planetary Defense Forces

Not every human world can wait for a major UNSC formation to arrive when trouble begins. Colonial militias, permanent garrisons, local security forces, and planetary defense units provide the first layer of protection across a civilization too large to defend everywhere at once. This episode examines the forces that guard settlements, infrastructure, spaceports, government facilities, and strategic positions before reinforcements appear. Their quality varies enormously. Some colonies maintain experienced personnel and heavy equipment; others rely on lightly trained units designed mainly for internal security or emergency response. During the Insurrection, local forces can become participants in political conflict rather than neutral defenders. During Covenant attacks, they may suddenly face alien armies whose technology exceeds anything their training anticipated. Planetary forces cannot usually defeat a major invasion alone, but they can delay landing operations, protect evacuations, defend critical installations, and provide local knowledge regular UNSC formations lack. For many colonists, these units are the military they actually know.