Possible Clues:

• Grace under pressure
• Self-confidence of a doctor behind Middle East organisation
• Cool look -- male wearing a lead
• Self-possession gets your pal over the mob
• The balm with the Po gives one self-confidence
• See apparently first doctor showing coolness
• Self-confident composure
• Coolness of pal mob troubled
• The assurance that there's a little plural in a mob
• Father is back. Behold, his degree in medicine will give him assurance (6)