A Federal military commander’s authority, in extraordinary emergency circumstances where prior authorization by the President is impossible and duly constituted local authorities are unable to control the situation, to engage temporarily in activities that are necessary to quell large-scale, unexpected civil disturbances because (1) such activities are necessary to prevent significant loss of life or wanton destruction of property and are necessary to restore governmental function and public order or (2) duly constituted Federal, state, or local authorities are unable or decline to provide adequate protection for Federal property or Federal governmental functions.