Several factors contributed to the Allies not dividing and occupying Italy after World War II:

The Allies invaded Sicily in 1943, leading to the fall of Mussolini's fascist government. Italy signed an armistice, ending hostilities and turning its forces over to the Allies. Hitler moved German forces into northern Italy to prevent losing the country entirely. Italy became more of a battleground than a hated enemy. The Soviet Union did not fight in Italy, so it had less interest in occupying it compared to Germany. Catholic and Italian American communities in the U.S. supported Italy as a potential ally against communism. Italy benefited from the European Recovery Program, joined NATO, and became an allie. The Allies invaded Sicily in 1943, leading to the fall of Mussolini's fascist government. Italy signed an armistice, ending hostilities and turning its military over to the Allies. Nazi Germany occupied northern Italy to prevent losing the entire country, making Italy more of a battleground than an enemy. The Soviet Union did not fight in Italy, so it had less interest in occupying the country compared to Germany. Catholic and Italian American communities in the U.S. supported Italy, arguing it could help combat communism. Italy benefited from the European Recovery Program, became a NATO founding member, and emerged as a unified, democratic nation. ​