To ban loans and embargo munitions would have been to give realistic expression to the isolation that the people and their President believed they enjoyed. But it would have closed off the wealth of unlimited orders, and Americans did not wish to suffer for their neutrality. Rather they hoped to make a good thing of it. With these two economic measures taken before the war was three months old, the fact, if not the illusion, of isolation was dead. —“How We Entered World War I,”
Barbara Tuchman

Based on the paragraph, what is the primary structure used by the author?