(1) In general.— The Secretary of Transportation shall investigate, determine, and keep current records of the ocean services, routes, and lines from ports in the United States, or in the territories and possessions of the United States, to foreign markets, which the Secretary determines to be essential for the promotion, development, expansion, and maintenance of the foreign commerce of the United States. In making such a determination, the Secretary shall consider and give due weight to
(A) the cost of maintaining each line;
(B) the probability that a line cannot be maintained except at a heavy loss disproportionate to the benefit to foreign trade;
(C) the number of voyages and types of vessels that should be employed in a line;
(D) the intangible benefit of maintaining a line to the foreign commerce of the United States, the national defense, and other national requirements; and
(E) any other facts and conditions a prudent business person would consider when dealing with the persons own business.