What foundational principle does every Marine adhere to regarding their military ethos?

The foundational principle that every Marine adheres to regarding their military ethos is that every Marine is a rifleman. This principle emphasizes the core belief that regardless of a Marine's specific job or role within the military, every individual is fundamentally trained to engage in combat. This mindset fosters a culture of readiness and adaptability, ensuring that all Marines can operate effectively in high-pressure situations and support one another as needed. By instilling this principle, the Marine Corps maintains a strong emphasis on individual responsibility, teamwork, and the capability to utilize firearms competently, which are essential elements of the Corps' overall mission.

This foundational belief underscores the importance of marksmanship and combat readiness, reinforcing the idea that all Marines share a common bond rooted in their primary role as defenders. The principle reflects the expectation of every Marine to uphold the highest standards of proficiency in their weapons handling, ensuring that they are never reliant solely on specialists to engage the enemy.