The purpose of National Security Directive (NSD) 28 was to ensure that the U.S. maintained the capability to meet sealift requirements in the event of crisis or war -- i.e., the availability of sufficient military and civil maritime resources to meet both defense deployment and essential economic requirements. To that end, it stipulated that the U.S. owned commercial fleet should be relied upon to provide sealift in peace, crisis and war, knowing that the U.S. might need to respond unilaterally to security threats in geographic areas not covered by alliance commitments. The flag fleet was to continue to rely on U.S. owned, controlled and allied shipping resources to meet commitments to established alliances. Further, the directive called on the departments of Defense and Transportation to work together to determine the capacity of the merchant marine industries to meet and provide sealift requirements and to incorporate national defense features in new and existing ships. The directive was careful to note, however, that government programs and policies would provide for an environment which fosters the competitiveness and industrial preparedness of all U.S. industries, including the maritime industry.