I love this quote by Colin Powell in "Leadership Secrets of Colin Powell" by Oren Harari:

"I want you to know you can count on me; I want to know that I can count on you. We may argue about which action to take, but I'll stick by you as we're arguing as long as you stick by me once a decision is made. No cover-your-butt moves are necessary from you; no knife-in-the-back will come from me."

That's great leadership.