Whenever the governor determines that, because of invasion, insurrection, riot, civil disorder, unlawful combination or conspiracy, catastrophe, natural or human caused disaster, or imminent danger thereof, the public safety and order cannot be preserved or the laws cannot be enforced by the civil authorities or the national guard, or as otherwise provided by law, the governor may call the Hawaii state defense force, or such part of it as may be required, into the active service of the State for the duration of the condition which required its call.