What is the single greatest "trait" you look for in a Leader?

One "trait" doesn't really measure a leader,but the ability to make a quick informed decision is essential in combat.

There isn't just one trait that I look for... But if I had to choose just one, I would look for integrity... In my Army experience, I have seen few leaders(NCO's) live the essence of the Creed of the Non-
Commissioned Officer... Mission, Soldier, Self! Too many are submerged in their own careers and social lives instead of building their team, mentoring their soldiers, and training the lower enlisted to become great NCO's... They are more than willing to throw their own soldiers under the bus to save their own asses, and this causes mistrust from their soldiers. As an NCO, I do my best to earn my (and other) soldiers' trust. I want them to know that I am there for them if and when they need me, and that I will stand by them even when they mess up. I also encourage them to do what is right for their career, as well as their health. I may not be the best NCO in existence, but I do my best with what I have...

Leads by example, not by force.

Sorry, I can't pick just one. I strive daily to maintain improve my own competency, character, and commitment, and those are the three traits I look for in other leaders.

Service to others

Humility...reference Good to Great by Jim Collins

Honesty and not afraid to fail

That you are present, that you communicate, lead by example

Trustworthiness (integrity)

Honor.