History
Department of Domestic Security and Defense is a department which secretly serves as a government cover for the organization Hydra, and in theory is dedicated to the security of the United States against scientific threats, such as superhuman individuals called mutants. He also conspires against the entire mutant community, from experiments to their supposed eradication. The Secretary of this Department is an anti-mutant military officer named William Stryker Jr..
After Stryker's conspiracy and illegal experiments were exposed, this department was succeeded by the Department of Mutant Affairs, although it was more tolerant towards mutants.