WASHINGTON — President Trump has long viewed foreign policy as a series of business deals, stripped of values and idealism. But his 633-word statement on Tuesday about the brutal killing of the Saudi dissident Jamal Khashoggi showed the extent to which he believes that raw, mercantilist calculations should guide the United States’ decisions about the Middle East and the wider world.

Mr. Trump made clear that he sees alliances as transactional, based on which foreign partners buy the most weapons. American jobs outweigh American values. And all countries act abhorrently, so an American president should never hold friends to different standards than enemies.

Tuesday’s message could become something of a blueprint for foreign leaders — a guide to how they might increase their standing in the eyes of the American president as well as how far they can go in crushing domestic critics without raising American ire.

It was also a revealing meditation on the role that Mr. Trump believes facts should play in political decision-making. The C.I.A. concluded that Crown Prince Mohammed bin Salman of Saudi Arabia had ordered Mr. Khashoggi’s killing, American officials said last week. But on Tuesday, the president dismissed not only that assessment but also the very process of seeking the truth, implying that it did not really matter anyway. (“Maybe he did and maybe he didn’t!” Mr. Trump wrote of Prince Mohammed.) Instead, the decisions of a president should be guided by what is best for the economy and the United States’ security.