All powers and functions conferred upon the Coast Guard, or the Commandant, by or pursuant to this title or any other law shall, unless otherwise specifically stated, be executed by the Commandant subject to the general supervision of the Secretary. In order to execute the powers and functions vested in him, the Commandant may assign personnel of the Coast Guard to duty in the District of Columbia, elsewhere in the United States, in any territory of the United States, and in any foreign country, but such personnel shall not be assigned to duties in any foreign country without the consent of the government of that country; assign to such personnel such duties and authority as he deems necessary; and issue rules, orders, and instructions, not inconsistent with law, relating to the organization, internal administration, and personnel of the Coast Guard.