What must be declared in order for the military and National Guard to be granted arrest authority?

The declaration of Martial Law is essential for the military and National Guard to be granted arrest authority. This situation allows for the military to take control of law enforcement duties and perform arrests when civilian law enforcement is unable to maintain order, often during severe emergencies, civil unrest, or major disaster situations. Under Martial Law, the normal operations of the legal system can be suspended, granting the military powers to enforce laws directly.

In contrast, a State of Emergency typically allows for certain procedures and measures to be enacted to provide assistance, but it does not inherently transfer arrest authority. National Alert may elevate readiness and preparedness but does not necessarily enable enforcement capabilities. Military Intervention usually refers to deploying military forces in foreign or domestic situations, while not specifically addressing the authority to make arrests. Thus, declaring Martial Law is the specific legal step that justifies the military's expanded role in law enforcement activities.