What is the climax in Hemingway's A Farewell to Arms?

The climax comes when Henry escapes after he and Piani
approach the Tagliamento River in the full swell of the Italian retreat. The Germans had
reinforced the Austrian troops, and the Italians were in full rout. Deserters, or those
who seemed to be deserters, were being detained at the bridge over the Tagliamento, then
executed on the spot. Henry is arrested, tied to a tree and about to be shot when he
breaks free and escapes to the relative safety of the water. He reaches the other side
of the shore and more relative safety.

His arrest and impending
execution by military police, who had that "beautiful detachment and devotion to stern
justice of men dealing in death without being in any danger of it [themselves],"
comprise the focal point of the climax, which might be said to encompass the entire
retreat. It is following Henry's escape that the ultimate course of the novel is set. As
Henry plunges into the water, arms are firing after him. When he reaches the other side,
after an incalculably long time in the cold water, the arms have quit firing. Henry's
sojourn in the water constituted his farewell to arms, symbolized by the silencing of
the firing. On dry land again, Henry turns his thoughts to Catherine and away from the
war after having said to himself of the war that "It was not my thing
anymore."