Jellico probably was nervous as all hell about the prospect of war. Unlike Riker though he checked his emotions at the door, was leading with confidence and resolved the situation, and he was fully ready if things went sour. I greatly enjoyed the character and the depth to him for a two episode guest star.
Plus Riker complaining about Jellico riding him to hard is just hypocrisy. He's been hard on every extra with a line save O'brien. Ro, Lavelle, and Barclay. Basically anyone outside the command clique he's standoffish towards. Jellico, unlike those people, wasn't about to put up with it and had the rank to back it up.