Identify a central idea of the selection from “how we entered world war i.” fear of losing territory in the southwest to mexico was the major factor in the united states’ entry into the war. a fear that democracy and freedom would suffer a terminal blow with a german victory compelled president wilson to ask congress to declare war. damage to us international trade and economic interests was the principal reason the united states decided to go to war. pressure from a public eager for war forced the president to bring the united states into world war i.