When does the federal government have sole authority to enforce laws on installations?

The federal government has sole authority to enforce laws on installations when it has exclusive jurisdiction. This means that the federal government maintains full control over the area and no state or local laws apply there. Exclusive jurisdiction grants the federal government the power to enforce its own laws, regulations, and ordinances without interference from state authorities. This is often the case on military bases and federal properties where the government needs to ensure a uniform application of laws pertinent to national security and operational integrity.

In contrast, concurrent jurisdiction allows both federal and state authorities to have some level of legal power in an area, which means that enforcement could be shared. Reciprocal jurisdiction involves arrangements between jurisdictions that allow for cross-authority enforcement, which does not grant sole authority to the federal government. Additionally, military orders, while authoritative within the military context, do not inherently grant exclusive law enforcement authority over an installation. Thus, exclusive jurisdiction is the key condition under which the federal government alone enforces laws.