In "Soldier's Home," why is Krebs' having trouble adjusting to life at home after having served as a soldier in the World War I?
Hemingway reports that Krebs served in the second division of the United States Marine Corps which fought at "Belleau Wood, Soissons, the Champagne, St. Mihiel and in the Argonne." At the Belleau Wood Marines fought hand to hand and with bayonets, sustaining over 8,000 casualties. The Marines helped stop the German offensive (and four more) which ultimately led to an Allied victory in the war.
Obviously the horrors Krebs saw deeply affected him. At first he didn't want to talk about the war but later he could find no one who wanted to listen:
Later he felt the need to talk but no one wanted hear about it. His town had heard too many atrocity stories to be thrilled by actualities. Krebs found that to be listened to at all he had to lie, and after he had done this twice he, too, had a reaction against the war and against talking about it.
Krebs lies probably attributed some act of heroism to himself and were an attempt to deal with what he went through, but when he would meet another veteran he could admit "that he had been badly, sickeningly frightened all the time." Because of the fear and stress he experienced in the war, Krebs simply wants his life at home to be uncomplicated. He lacks motivation and seems alienated from his family.
Today, doctors might diagnose Krebs malaise as combat related post-traumatic stress disorder. That disorder usually causes veterans to have a difficult time adjusting to regular life after being in the heat of battle where death could be imminent. Many of Hemingway's heroes in his short stories and novels suffered from PTSD. The term would not be officially used until after the Vietnam War, but it is recognized as a significant problem for returning warriors. Charles Coleman has written an excellent book, PTSD and Hemingway's "A Way You'll Never Be": The Mark of Confidence postulating that Hemingway's character Nick Adams suffered from the disorder. The same could probably be said for Harold Krebs.