Which branch of the military typically has authority over the National Guard in times of national emergency?

In times of national emergency, the National Guard operates under the authority of the federal government. This is primarily facilitated through a process known as federal activation, where the President can federalize National Guard units, thereby placing them under federal command and control. This means that the federal government can mobilize the National Guard for national defense, disaster response, or other critical needs.

While the President, as the Commander-in-Chief, has direct authority over the National Guard when it is federalized, the process involves both executive decision-making and legislative support, illustrating the collaborative nature of military governance in crisis situations. The involvement of Congress primarily pertains to funding and legislative aspects but does not directly manage the operational control in emergency scenarios.

Understanding this structure is crucial, as it highlights the unique dual-role of the National Guard—operating under state authority in peacetime and shifting to federal authority during national emergencies, which distinguishes it from active duty service members who are always under federal command.