Final answer:
The sense of brotherhood, interdependence, and determination to triumph for U.S. Marines typically develops during basic training and is cemented through shared experiences and hardships during combat, as exemplified at Iwo Jima during World War II.
Step-by-step explanation:
The sense of brotherhood, interdependence, and determination to triumph in a Marine's career often emerges during the foundational experience of basic training, where the old identity is stripped away in favor of a new, shared identity. This bonding experience is reinforced in the field through shared hardships and experiences, epitomized by historical moments such as the raising of the American flag atop Mt. Suribachi, Iwo Jima, on February 23, 1945. The intense and life-threatening conditions of combat, where Marines depend on each other for survival, navigation of morally complex situations, and the completion of their missions, foster an even greater sense of reliance and unity.
Throughout their careers, Marines are inculcated with core values and undergo experiences that deepen their bonds with one another—extending beyond the individual to a collective sense of identity and purpose. In addition to basic training, the brotherhood is solidified in combat, as seen in World War II and later conflicts, where Marines relied on each other amidst a landscape where the front lines were everywhere, and the only certainty was their comrades-in-arms.
The history and success of the U.S. Marine Corps in campaigns, as well as their evolution with societal trends such as race dynamics, underscore the significance of interdependence in military culture and the shared goal of mission success, which is a source of pride and a recurring theme in their storied history.