Which act restricts the use of the military for domestic enforcement?

The Posse Comitatus Act is the legislation that restricts the use of the military for domestic enforcement of laws. This act was passed in 1878, primarily to limit the federal government's ability to use the military to enforce domestic policies or laws, particularly in the wake of Reconstruction in the South. The fundamental principle of the Posse Comitatus Act is to maintain a clear distinction between civilian law enforcement and military functions, ensuring that the military does not play a role in enforcing civil law except in extraordinary circumstances.

This act has played a crucial role in shaping the relationship between military and civilian authorities in the United States, reinforcing the idea that law enforcement should primarily be conducted by civilian agencies. While there are exceptions provided under certain conditions—such as the Insurrection Act, which allows for military involvement in domestic disturbances—the Posse Comitatus Act remains a significant barrier to the routine use of military force in domestic law enforcement scenarios.