Marx is a combat veteran who recently returned from the European theater. He believes he has developed an "infantryman's heart" that insulates him from intense emotion. This insulation helps him function in the harsh military environment. Stationed at Camp Crowder, his hardened exterior is tested when young Jewish trainees begin appealing to his shared heritage. He discovers a buried kindness within himself that makes him susceptible to the calculated tactics of the soldiers seeking special treatment.

Captain Barrett is the commanding officer at Camp Crowder who recently returned stateside after being wounded in Europe. He is a brusque, fiery man who values bravery and strict adherence to military regulations. He displays little patience for cultural nuances and quickly defaults to negative stereotypes when frustrated by the trainees' requests for religious accommodations.

Grossbart is a nineteen-year-old trainee waiting to find out if he will see combat in the Pacific. He is opportunistic and emotionally intelligent, regularly using his Jewish identity to manipulate his superiors for personal gain. He easily works the military bureaucracy by leveraging the genuine faith of his peers and employing calculated flattery. This allows him to secure weekend passes and avoid mundane tasks.

Fishbein is a young Jewish trainee from New York stationed at Camp Crowder. He eagerly participates in Grossbart's maneuvers to avoid difficult duties and gain off-base privileges. While he shares Grossbart's self-interest, he lacks his friend's charisma. He occasionally acts clumsy in conversation and nearly exposes their true intentions.

Halpern is a deeply devout Jewish trainee dealing with the stress of basic training. Unlike his opportunistic friends, his religious dedication is authentic, causing him real distress over the non-kosher food served at the camp. He tags along with Grossbart and Fishbein largely out of obligation, while they use his genuine faith to validate their pleas for exceptions.

Major Ben Ezra serves as the Jewish chaplain at Camp Crowder. He provides practical guidance to the young trainees, specifically advising them on how to manage their dietary restrictions when faced with non-kosher army rations.

Samuel is Private Sheldon Grossbart's father. His name appears on correspondence sent to politicians to secure better conditions for his son, which demonstrates the familial connections that influence Sheldon's standing at the camp.

Corporal LaHill is the Charge of Quarters at the barracks in Camp Crowder. He executes Marx's orders to allow Jewish personnel to attend religious services instead of performing routine cleaning duties.