Why does Phineas say there is no war in 1943

Throughout the novel, the boys attending Devon School prepare to enter World War II following graduation. Despite the constant news covering the war and enthusiasm surrounding America's involvement, Finny purposely denies the existence of a world war. Finny had been by far the best athlete in the school before Gene shook him from a tree and broke his leg. Tragically, Finny never regained his old athleticism and would not be able to enlist in the armed forces like the other boys. Not being able to enlist in the Army torments Finny throughout the novel, and he begins denying the existence of the war. Despite the overwhelming evidence to the contrary, Finny insists that the war is simply a hoax concocted and propagated by wealthy old men. Finny's purposeful denial is his way of psychologically protecting himself. Devastated that he will not be able to participate in the war, Finny finds it easier to pretend that the war does not exist. After Finny breaks his leg for the second time, he admits to Gene in the infirmary why he denied the existence of the war. Finny tells Gene,

I’ll hate it everywhere if I’m not in this war! Why do you think I kept saying there wasn’t any war all winter? I was going to keep on saying it until two seconds after I got a letter from Ottawa or Chungking or some place saying, "Yes, you can enlist with us" (Knowles, 103).