In the leadership doctrine of the United States Army, in which core leader competency is the warrior ethos most clearly exemplified?

Introduction / Context:
The United States Army defines a set of core leader competencies that describe how leaders should behave and perform. One central idea is the warrior ethos, a value system that emphasises putting the mission first, never accepting defeat, never quitting and never leaving a fallen comrade. This question asks which leadership competency best reflects or exemplifies that warrior ethos.

Given Data / Assumptions:

• The question is about US Army leadership doctrine, not general leadership theory.
• We are asked to link the warrior ethos to one core leader competency.
• Options: Leading by example, Communicating effectively, Developing others and Achieving results.
• The warrior ethos is about personal behaviour and role modelling.

Concept / Approach:
The warrior ethos is not only about internal beliefs but also about how leaders behave in front of their soldiers. A leader who lives the warrior ethos must demonstrate courage, commitment and resilience in daily actions, thereby setting a clear standard for subordinates. This is captured in the competency "Leading by example", which focuses on the leader's personal conduct as a model for others. While communication, development and results are important, the warrior ethos is most directly expressed through exemplary behaviour.

Step-by-Step Solution:
Step 1: Recall the typical wording of the warrior ethos: putting the mission first, never accepting defeat, never quitting and never leaving a fallen comrade. Step 2: Recognise that these commitments are expressed through the leader's own actions rather than only through speeches or written instructions. Step 3: Link this behavioural emphasis to the core competency "Leading by example", which stresses that leaders must personally live the values they expect from their soldiers. Step 4: Compare with the other competencies: Communication, Developing others and Achieving results are important but do not directly capture the essence of the warrior ethos as strongly as leading by example. Step 5: Conclude that the core leader competency which exemplifies the warrior ethos is Leading by example.

Verification / Alternative check:
Leadership manuals and explanations of US Army doctrine frequently highlight that the warrior ethos must be visible in the leader's own behaviour. They explain that soldiers watch their leaders closely, and a leader who lives the warrior ethos in training and in combat situations provides a powerful model. This matches the idea that "Leading by example" is the competency where the warrior ethos is most fully displayed.

Why Other Options Are Wrong:
Communicating effectively: Good communication is essential, but simply talking about courage or resilience does not fully capture the warrior ethos unless the leader also lives those values in action.
Developing others: Training and mentoring subordinates are important leadership tasks, yet they are not the most direct expression of the warrior ethos, which centres on personal commitment and courage.
Achieving results: Delivering results is crucial for any leader, but results alone do not show whether the leader embodies the warrior ethos values such as never leaving a comrade behind.

Common Pitfalls:
Candidates sometimes choose Achieving results because it sounds like a broad summary of leadership success. Others may think of communication as the key competency because leaders often talk about values. However, the core idea of the warrior ethos is that values must be lived, not just spoken, so the safest choice in exam questions is Leading by example, which directly ties behaviour to ethos.

Final Answer:
The warrior ethos is most clearly exemplified in the core leader competency of Leading by example.