Avoid having your ego so close to your position that when your position falls, your ego goes with it. - Colin Powell

You are the leader and the troops will reflect your emotions.

Few people make sound or sustainable decisions in an atmosphere of chaos. The more serious the situation, usually accompanied by a deadline, the more likely everyone will get excited and bounce around like water on a hot skillet. At those times I try to establish a calm zone but retain a sense of urgency. Calmness protects order, ensures that we consider all the possibilities, restores order when it breaks down, and keeps people from shouting over each other. You are in a storm. The captain must steady the ship, watch all the gauges, listen to all the department heads, and steer through it. If the leader loses his head, confidence in him will be lost and the glue that holds the team together will start to give way. So assess the situation, move fast, be decisive, but remain calm and never let them see you sweat.

Diplomacy is listening to what the other guy needs. Preserving your own position but listening to the other guy. You have to develop relationships with other people so when the tough times come, you can work together.