The Sad Sack (1957) on Netflix

Private Meredith Bixby is so out of step in the Army that his six weeks of planned basic training has now stretched to 17 months. After he loses a tank, WAC Major Shelton, a psychologist, is assigned to make a good soldier out of him. She requests Corporal Dolan and Private Stan Wensalawsky to help with the training. Dolan and Stan both have scores to settle with Bixby and their "guidance" leads to more mishaps. Sergeant Pulley has them shipped out to Morocco. On leave in North Africa, Bixy wanders alone into a bar, has a few Moroccan Delights, which he thinks are malted milks, and becomes convinced that exotic singer-dancer Zita is THE girl for him. To protect him, Dolan tells him some lies about Zita, and Bixby, in despair, joins the Suicide Division of the Foreign Legion. He is kidnapped by a band of Arabian plotters and, guarded by the knife-happy Abdul, is ordered to assemble a stolen American cannon. Zita learns of his plight and gets Dolan and Stan to join her in a rescue mission.