Certain controls were imposed on the staffing of American vessels. A statute of December 17, 1941 made it unlawful to employ any person or to permit any person to serve as radio operator abroad any vessel (other than a vessel of foreign registry) if the Secretary of the Navy disapproved the employment for any specified voyage, route, or area of operation and had notified the master of the vessel of the disapproval prior to the vessel’s departure.[426] In 1934 a new stipulation permitted the Commission to suspend the rule requiring radio operators to have at least six months service before being qualified as a radio operator. However, suspension of this qualification could not be retained once the emergency had been terminated.[427] _Control of Foreign Vessels in American Waters_: The Neutrality Act of 1935, as amended in May 1937, empowered the President to place special restrictions on the use of the ports and territorial waters of the United States. The restrictions which could be imposed involved limiting access to American ports and territorial waters by the submarines or merchant vessels of a foreign state. Special restrictions could be imposed at the President’s discretion once he determined that such restrictions were needed to protect the commercial interests of the United States and its citizens, or to promote the security of the United States. Once limitations on port usage had been imposed, it became unlawful for any foreign submarine or armed merchant vessel to enter a port or territorial water of the United States. Only the President could prescribe the conditions and circumstances which would justify an exception to the rule.[428] On October 18, 1939, President Roosevelt issued Proclamation No. 2371 declaring it unlawful for belligerent submarines, whether commercial or ships of war, to enter the ports or territorial waters of the United States except when forced into such ports by _force majeure_.[429] The Panama Canal Zone was exempted from this order. Following enactment of the November 4, 1939 amendment to the Neutrality Act,[430] a new proclamation with identical provisions was promulgated in conformity with the revised law.[431] CHAPTER VII CONTROL OF COMMUNICATIONS A contemporary “revisionist” school of historians devoted to a reappraisal of accepted views of the cause and effect of American participation in the Second World War, attributes significance to the charge that the Roosevelt and Truman Administrations selected, withheld, and released data to historians in a manner calculated to distort the reasons for American involvement in that war.[432] Similar charges of selective withholding or release of information, have, of course, been levied against the Eisenhower Administration.